Microsoft 365 Alert – Service Degradation – Microsoft 365 for the web – Users can’t open new files in Excel for the web or use the “Create a copy” function – RESOLVED

18/12/2025 8:33:00 AM

NHSmail Reference: INC46708269

Microsoft Reference: OO1198794

Issue Status: RESOLVED

Issue Description: Users couldn’t open new files in Excel for the web or use the “Create a copy” function.

More info: Users likely would have encountered this scenario mostly when attempting to open a new file in Excel on the web from SharePoint Online or Microsoft OneDrive. Any scenario that included triggering an action to open a new file would have been affected also.

Users opening a file in Excel for the web would have encountered a blank white section where the data was expected to populate and would have seen a message in the bottom-right section indicating that the file was still loading.

Final Update: 18/12/2025 08:33:00 AM – Microsoft received reports of an issue in which users couldn’t open new files in Excel for the web or use the “Create a copy” function and determined that a recent feature update resulted in malformed URLs in the file path process preventing a core resource that facilitates Excel on the web file loading from completing. They have disabled the portion of this update that resulted in the impact and confirmed through monitoring the log errors associated with the issue are no longer occurring.

Scope of impact: Your organization was affected by this event, and any user attempting to open a new file or use the “Create a copy” save feature in Excel for the web was impacted.

Root cause: A recent feature update resulted in malformed URLs in the file path process preventing a core resource that facilitates Excel on the web file loading from completing.

Next Steps: Microsoft are reviewing their feature update testing and validation processes to better detect issues affecting Excel on the web file access prior to deployment.