Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may have been unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may have only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels were long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may have not been visible. As a workaround, impacted users could zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Final status: We've confirmed through testing with a subset of affected users that reverting the recent configuration change has remediated the impact. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may have been impacted. Start time: Tuesday, August 18, 2026, at 1:30 PM UTC End time: Thursday, September 3, 2026, at 1:46 PM UTC Root cause: A recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that was preventing Teams channel tabs from rendering correctly. Next steps: - We're reviewing the offending configuration change to understand why the regression wasn't identified during our pre-deployment testing processes, so that we can prevent similar issues from occurring in the future. This is the final update for the event.

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels are long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may not be visible. As a workaround, impacted users can zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Current status: We've completed the reversion of the offending configuration change and are reaching out to a number of impacted users to confirm that this action successfully resolved the issue. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may be impacted. Start time: Tuesday, August 18, 2026, at 1:30 PM UTC Root cause: A recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that is preventing Teams channel tabs from rendering correctly. Next update by: Thursday, September 3, 2026, at 4:00 PM UTC

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels are long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may not be visible. As a workaround, impacted users can zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Current status: We’re working to revert the offending configuration change. We expect that this will process will be complete and the issue resolved by our next scheduled update. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may be impacted. Start time: Tuesday, August 18, 2026, at 1:30 PM UTC Root cause: A recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that is preventing Teams channel tabs from rendering correctly. Next update by: Thursday, September 3, 2026, at 2:30 PM UTC

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels are long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may not be visible. As a workaround, impacted users can zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Current status: We’re working to revert the offending configuration change. We expect that this will process will be complete and the issue resolved by our next scheduled update. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may be impacted. Start time: Tuesday, August 18, 2026, at 1:30 PM UTC Root cause: A recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that is preventing Teams channel tabs from rendering correctly. Next update by: Thursday, September 3, 2026, at 2:30 PM UTC

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels are long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may not be visible. As a workaround, impacted users can zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Current status: We’ve determined that a recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that is preventing Teams channel tabs from rendering correctly. We’re deploying a fix to mitigate the impact and conducting internal validation to confirm it successfully resolves the issue. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may be impacted. Start time: Tuesday, August 18, 2026, at 1:30 PM UTC Root cause: A recent configuration change associated with a user interface modernization effort inadvertently introduced a regression that is preventing Teams channel tabs from rendering correctly. Next update by: Thursday, September 3, 2026, at 12:30 PM UTC

Title: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels User impact: Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels. More info: Users may only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels are long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may not be visible. As a workaround, impacted users can zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs. Current status: We're reviewing HTTP Archive (HAR) files and Teams client logs from a number of impacted users to determine the root cause and identify mitigation options. Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may be impacted. Next update by: Thursday, September 3, 2026, at 11:00 AM UTC