Some users may be unable to access SharePoint Online sites configured with Authentication Context

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Users receive the following error message:
"Server Error in '/' Application."

As a workaround, users may be able to temporarily access the affected content by first clearing internet browser cookies and navigating to the root site collection before opening the direct link. Users can also open a new browser tab on the same session and access the site. The link may work as well.

Current status: The deployment is progressing as expected and users will see relief as it progresses. We expect the release to complete, mitigating impact for all users by the next scheduled update.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted. This information may be updated as our investigation continues.

Start time: Sunday, August 23, 2026, at 2:38 AM UTC

Root cause: A recent SharePoint Online code change intended to update authentication processing resulted in Authentication Context requests not being processed as expected, preventing some users from accessing affected sites.

Next update by: Friday, September 4, 2026, at 7:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Users receive the following error message:
"Server Error in '/' Application."

As a workaround, users may be able to temporarily access the affected content by first clearing internet browser cookies and navigating to the root site collection before opening the direct link. Users can also open a new browser tab on the same session and access the site. The link may work as well.

Current status: We've identified that a recent SharePoint Online code change intended to update authentication processing resulted in Authentication Context requests not being processed as expected, preventing some users from accessing affected sites. We've developed a fix to revert the offending change and have initiated deployment to the affected environments. We're monitoring the deployment to ensure successful completion, and as the fix progresses, some users may experience impact relief. We'll provide a resolution timeline once available.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Start time: Sunday, August 23, 2026, at 2:38 AM UTC

Root cause: A recent SharePoint Online code change intended to update authentication processing resulted in Authentication Context requests not being processed as expected, preventing some users from accessing affected sites.

Next update by: Wednesday, September 2, 2026, at 7:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Users receive the following error message:

"Server Error in '/' Application."

As a workaround, users may be able to temporarily access the affected content by first clearing internet browser cookies and navigating to the root site collection before opening the direct link. Users could also open a new browser tab on the same session and access the site. The link may work as well.

Current status: We've determined that reverting the update suspected of causing this issue isn't a viable path to remediation. We're reviewing alternative solutions to confirm the impact and resolve the problem.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Tuesday, September 1, 2026, at 7:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Users receive the following error message:

"Server Error in '/' Application."

As a workaround, users may be able to temporarily access the affected content by first clearing internet browser cookies and navigating to the root site collection before opening the direct link. Users could also open a new browser tab on the same session and access the site. The link may work as well.

Current status: We've identified a recent change which we suspect may be leading to the impact, and we're determining whether rolling the change back is a viable option to remediate impact.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Monday, August 31, 2026, at 10:30 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Current status: Our investigation of the Authentication Context configuration is ongoing as we work to confirm the source of the impact before we can begin to develop a mitigation strategy.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Monday, August 31, 2026, at 8:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Current status: In addition to our HAR analysis, we're further reviewing the Authentication Context configuration to understand whether this is where the impact originates.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Monday, August 31, 2026, at 6:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Current status: We're reviewing HAR files that compare successful access requests initiated through the root site collection with failing direct-link requests to determine why the behavior differs and identify next steps to mitigate impact.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Monday, August 31, 2026, at 4:00 PM UTC

Title: Some users may be unable to access SharePoint Online sites configured with Authentication Context

User impact: Users may be unable to access SharePoint Online sites configured with Authentication Context.

More info: Specifically, users are unable to access SharePoint Online sites configured with Authentication Context through sensitivity labels.

Current status: We've reproduced the issue in our testing environment and are reviewing HTTP Archive (HAR) logs to determine why direct links fail when Authentication Context is enabled through sensitivity labels.

Scope of impact: Some users attempting to access SharePoint Online sites configured with Authentication Context through sensitivity labels may be impacted.

Next update by: Monday, August 31, 2026, at 2:30 PM UTC