Admins couldn’t upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center

Title: Admins couldn’t upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins couldn’t upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. Final status: We’ve confirmed that the fix is fully deployed across all impacted environments. Admins can now use the New-UnifiedGroup cmdlet in PowerShell to convert Distribution Lists to Unified Groups: New-UnifiedGroup -DlIdentity -DeleteDlAfterMigration Admins who run the Upgrade-DistributionGroup cmdlet directly will continue to encounter failures. This cmdlet may be deprecated in the future. Scope of impact: Impact was specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. Start time: Friday, October 24, 2025, at 11:32 AM UTC End time: Wednesday, April 8, 2026, at 4:33 AM UTC Root cause: A timing issue during a recent migration causes backend systems to act before directory changes were fully synchronized, resulting in impact. Next steps: - We’re considering deprecating the Upgrade-DistributionGroup cmdlet in the future. This is the final update for the event.

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. More info: As a workaround, admins may be able to run the following command to mitigate impact. In Admin PowerShell, Run: New-UnifiedGroup -DlIdentity Current status: We’ve deployed the fix to approximately 50% of the affected environment after fixing the issue that was causing the deployment to be delayed. We anticipate being able to provide a completion timeline by our next scheduled update. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Start time: Friday, October 24, 2025, at 11:32 AM UTC Root cause: A timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. Next update by: Tuesday, April 14, 2026, at 11:00 AM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We’ve deployed the fix to approximately 10% of the affected environment. We’re investigating the cause of the deployment delay and exploring alternative approaches to accelerate the rollout. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Start time: Friday, October 24, 2025, at 11:32 AM UTC Root cause: A timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. Next update by: Friday, April 3, 2026, at 11:00 AM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: The deployment of the fix is progressing as anticipated, and we expect this to be complete and impact remediated by our next scheduled update. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Start time: Friday, October 24, 2025, at 11:32 AM UTC Estimated time to resolve: Wednesday, April 1, 2026 Root cause: A timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. Next update by: Wednesday, April 1, 2026, at 9:30 AM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We’re continuing to monitor the fix as it deploys across the impacted environments. We anticipate that the deployment should complete by Thursday, April 2, 2026. Once deployment has completed, the fix will be enabled to restore functionality. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Start time: Friday, October 24, 2025, at 11:32 AM UTC Estimated time to resolve: Thursday, April 2, 2026 Root cause: A timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. Next update by: Thursday, April 2, 2026, at 10:30 AM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We've determined that a timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. This is leading to failures during group configuration, preventing the Distribution List from successfully upgrading to a Unified Group. We're monitoring the deployment fix as it saturates across all impacted environments, which is taking longer than anticipated due to additional validation steps. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Start time: Friday, October 24, 2025, at 11:32 AM UTC Root cause: A timing issue during a recent migration is causing backend systems to act before directory changes are fully synchronized. Next update by: Wednesday, March 18, 2026, at 11:30 AM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We're proceeding with our deployment of the fix across all impacted environments and expect completion by Tuesday, March 17, 2026. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Estimated time to resolve: Tuesday, March 17, 2026 Next update by: Tuesday, March 17, 2026, at 12:00 PM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We're continuing to deploy the fix across all impacted environments and expect completion by Monday, March 16, 2026. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Estimated time to resolve: Monday, March 16, 2026 Next update by: Monday, March 16, 2026, at 12:00 PM UTC

Title: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center User impact: Admins can’t upgrade groups from Distributions Lists to Unified Groups using PowerShell or the Exchange admin center. Current status: We’ve developed a new fix and validated that it works in our testing environment. We’re currently deploying the fix across all impacted environments. Deployment is expected to complete by Monday, March 16, 2026. We’ll continue to monitor deployment progress and share updates accordingly. Scope of impact: Impact is specific to some admins attempting to upgrade groups from Distribution Lists to Unified Groups using PowerShell or the Exchange admin center. This section may be updated as our investigation continues. Estimated time to resolve: Monday, March 16, 2026 Next update by: Thursday, March 12, 2026, at 12:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We've determined that our previous fix did not successfully mitigate impact in the testing environment. We’ve now implemented an alternative fix in the test environment and will share an update on its effectiveness in our next scheduled communication. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation. continues. Next update by: Monday, March 2, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing to test the fix within our internal testing environment. However, due to the complexity of the changes, this testing is expected to take an extended amount of time. We will share further details once testing has completed. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, February 27, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're deploying the fix to our test environment and expect this process to complete by our next scheduled update. After the deployment completes, we'll be able to validate its effectiveness before deploying to the affected environments. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, February 13, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We’ve determined that the previously mentioned fix didn't successfully mitigate impact in our testing environment. As a result, we’ve developed an additional fix and are preparing to deploy it to our test environment to validate its effectiveness before deploying it to affected environments. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Thursday, February 12, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're progressing with our validation of the fix to ensure its efficacy. We'll provide a completion timeline when one becomes available. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Tuesday, February 10, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing to validate the fix to ensure its efficacy. We'll provide a completion timeline when one becomes available. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, February 6, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We've begun validation on the fix to ensure its efficacy. We'll provide a completion timeline when one becomes available. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Wednesday, February 4, 2026, at 1:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: After evaluating all available logging, we've identified a fix to safely resolve the impact. We're in the final stages of its development process and once the fix is ready, we will first deploy it to our test environment for validation. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Wednesday, February 4, 2026, at 8:00 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We expect that the fix will complete deployment to our internal testing environment, allowing us to validate its efficacy by the time of our next scheduled update. Additionally, we’re reaching out to a subset of affected users to provide Fiddler trace logs to assist us in validating that the previously mentioned timing-related issue during group creation is leading to impact and subsequently expedite the ongoing deployment of the aforementioned fix. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Monday, February 2, 2026, at 8:00 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We've encountered an issue preventing us from safely rolling out the code changes we were previously theorizing may be able to resolve the issue. We've identified that due to the complexity of the involved request flow and low volume of data associated with the impacted scenario, our internal reproduction of the issue is insufficient to conclusively validate our root cause theory without making changes to enhance our service logging specific to this scenario. We're evaluating options for implementing advanced logging and data collection methods to assist us in identifying our next steps towards remediation, as well as reassessing our options for safely deploying our potential fix. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, January 30, 2026, at 8:00 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We’re proceeding to work on the fix to ensure directory cache information is refreshed correctly across all servers. We’re also progressing our deployment validation and now expect to provide a completion timeline by our next scheduled update. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Root cause: A timing-related issue during group creation across backend systems where service requests are processed before directory information has fully refreshed across all servers, leading to impact. Next update by: Wednesday, January 28, 2026, at 7:00 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We’re actively working on the fix to ensure directory cache information is refreshed correctly across all servers. We’re progressing our deployment validation and expect to provide a completion timeline by our next scheduled update. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Root cause: A timing-related issue during group creation across backend systems where service requests are processed before directory information has fully refreshed across all servers, leading to impact. Next update by: Tuesday, January 27, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We've identified a timing-related issue during group creation across backend systems where service requests are processed before directory information has fully refreshed across all servers, leading to impact. We're deploying a fix to ensure directory cache information is refreshed correctly across all servers and expect to provide completion timeline by our next scheduled update. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Root cause: A timing-related issue during group creation across backend systems where service requests are processed before directory information has fully refreshed across all servers, leading to impact. Next update by: Monday, January 26, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing our review of the latest collected error logs and service data to gain further insight into the underlying source of impact and determine our next steps. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, January 23, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: After initial difficulties with acquiring specific logs from the impacted service, we've successfully managed to gather the needed error logs to help our investigation into the root cause of impact. We're analyzing these, along with previous data, to help inform our next troubleshooting steps and strategy to resolve the issue. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Friday, January 23, 2026, at 8:30 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing our efforts to gather and analyze additional service logging as we continue to work towards gathering data from an internal reproduction of the issue. Due to the complexity of the scenario, we're anticipating it may require some additional time before we can determine our options for mitigation. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Thursday, January 22, 2026, at 8:30 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: The previously mentioned log analysis to help understand why impact is occurring and to identify a strategy to resolve impact is ongoing. In parallel, we’re working to reproduce the issue internally to help aid our root cause investigation. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Wednesday, January 21, 2026, at 8:30 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing our analysis of the diagnostic logs, along with request IDs and error logs, to help identify the underlying root cause of impact and to inform our next steps to resolve the impact. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This section may be updated as our investigation continues. Next update by: Wednesday, January 21, 2026, at 2:30 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: Our analysis of the diagnostic logging is progressing as we work to identify the source of the issue and inform our next steps towards developing a strategy to resolve the impact. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Next update by: Wednesday, January 21, 2026, at 12:30 AM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're proceeding with our analysis of the diagnostic logs, to isolate the underlying root cause of impact and formulate a mitigation plan. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Next update by: Tuesday, January 20, 2026, at 6:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're continuing to analyze the diagnostic logs to isolate the root cause of impact and develop a fix. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Next update by: Monday, January 19, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We've collected diagnostic logs and we're analyzing them to isolate the root cause of impact and develop a fix. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Next update by: Wednesday, January 14, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're obtaining diagnostic logs to help us isolate the root cause of impact and formulate a mitigation plan. Scope of impact: Impact is specific to some admins attempting to upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Next update by: Tuesday, January 13, 2026, at 3:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: Our efforts to review logs, group creation and deletion processes, and environmental differences to reach a mitigation plan and root cause analysis is ongoing. Scope of impact: Your organization is affected by this event, and admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This information may be updated as our investigation continues. Next update by: Monday, January 12, 2026, at 2:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We’re continuing with our review logs, group creation and deletion processes, and environmental differences to find the cause of the upgrade issue. Scope of impact: Your organization is affected by this event, and admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This information may be updated as our investigation continues. Next update by: Friday, January 9, 2026, at 2:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We’re currently reviewing logs, group creation and deletion processes, and environmental differences to find the cause of the upgrade issue. Scope of impact: Your organization is affected by this event, and admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This information may be updated as our investigation continues. Next update by: Wednesday, January 7, 2026, at 2:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're reviewing system logs to isolate the origin of this issue. Scope of impact: Your organization is affected by this event, and any admin can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. This information may be updated as our investigation continues. Next update by: Tuesday, January 6, 2026, at 2:00 PM UTC

Title: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center User impact: Admins can’t upgrade groups from distributions lists to unified groups from PowerShell and the Exchange admin center. Current status: We're investigating a potential issue in which admins can’t upgrade groups from distributions lists to unified groups from both PowerShell and the Exchange admin center and checking for impact to your organization. We'll provide an update within 30 minutes.