On macOS Big Sur 11.7.11, the corrective action is to update macOS first, then update Office to a supported version.
Starting July 13, 2026, Office apps on unsupported macOS versions can enter reduced functionality mode: files can open and print, but cannot be edited, saved, or created. Microsoft states this affects Microsoft 365 subscribers and some non-subscription Office versions on macOS. For most users, updating the OS and then updating Office resolves it.
What to do:
- In an Office app, check which license/version is active:
- Open Word.
- Select Word > About Word.
- If it shows Microsoft 365, it is using the subscription build.
- Update macOS from Big Sur to a supported macOS version.
- Big Sur is older, and the documented fix for reduced functionality is to update the operating system first.
- After macOS is updated, update Office:
- Open any Office app such as Excel or Word.
- Select Help > Check for Updates.
- Install the latest available Office updates.
- Test saving again in Excel.
If saving still fails after the OS and Office are updated, try these Excel recovery steps to avoid losing work:
- Use File > Save As and save with a new file name.
- Save to an alternative drive/location.
- Move the worksheets to a new workbook:
- Press Shift+F11 to add a filler sheet.
- Select the first sheet, hold Shift, and select the last sheet to group them except the filler.
- Right-select the grouped sheets and select Move or copy.
- In To Book, select (New Book), then select OK.
- Save as a different file type, such as .xlsx or .xlsm.
Also check whether the save location allows saving. Excel requires read, write, modify, and delete permissions to the folder. If saving to an external or network drive, a connection problem can also cause save failures.
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