Microsoft 365 Alert – Service Degradation – Microsoft Power Automate – Some users may be missing options to open files using custom file handlers in Microsoft OneDrive – RESOLVED

16/04/2026 17:25:00 PM

NHSmail Reference: INC46800694

Microsoft Reference: OD1281099

Issue Status: RESOLVED

Issue Description: Users may be missing options to open files using custom file handlers in OneDrive.

Final Update: 16/04/2026 17:25:00 PM– Microsoft has confirmed that a recent service update to OneDrive changed how custom file handlers were processed, resulting in impact. We completed a rollback of the identified updates responsible for this and confirmed through service-side testing as well as testing with previously affected users that this is mitigated. Due to cache storage, this can take up to 48 hours to resolve for all users. If users are in need of immediate remediation, please follow the articles below:

https://learn.microsoft.com/en-us/onedrive/developer/file-handlers/?view=odsp-graph-online&source=r…

https://learn.microsoft.com/en-us/onedrive/developer/file-handlers/reset-cache?view=odsp-graph-onli…

Scope of impact: A recent service update to OneDrive changed how custom file handlers are processed, which resulted in impact.

Next update by: Microsoft are continue our review of the impacting update to better understand how the change resulted in impact and what we can do to improve our pre-deployment processes to identify and resolve similar issue