Try these steps in order:
- Update Office first
- Open any Office app.
- Go to File > Account > Update Options > Update Now.
- If the issue is on Office for Mac, go to Help > Check for Updates.
- Save again after the update.
- Save to a different local folder
- Try Documents or Desktop instead of the current location.
- This helps confirm whether the current folder has a permission or sync problem.
- If the file is in OneDrive, check OneDrive status
- Make sure OneDrive is running and signed in.
- If Files On-Demand is enabled, install the latest Office updates, because a known issue could cause saves to fail.
- Repair the document
- In Word, select File > Open > Browse.
- Select the file without opening it.
- Select the arrow next to Open, then choose Open and Repair.
- Try saving the repaired file.
- Start Word without add-ins
- Press Windows + R.
- Type
winword /aand press Enter. - If saving works in this mode, the problem is likely related to an add-in or template.
- If Adobe Acrobat 7.0 PDFMaker is installed, remove its Office add-in entries
- This issue can prevent Word from saving changes.
- Warning: registry changes can cause serious problems if done incorrectly. Back up the registry first.
- Remove these add-in entries if present:
-
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Word\Addins\PDFMaker.OfficeAddin -
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Excel\Addins\PDFMaker.OfficeAddin -
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Outlook\Addins\PDFMOutlook.PDFMOutlook
-
- Reset Word’s Data registry key
- If Word still cannot save, a damaged Word Data key may be the cause.
- Warning: this resets some Word settings to defaults. Back up the registry first.
- Close all Office apps.
- Open Registry Editor.
- Go to:
-
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Data
-
- Export the key, then delete Data.
- Start Word again.
- If needed, reset the Word Options registry key
- Warning: this also resets Word options.
- Go to:
-
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Options
-
- Export the key, then delete Options.
- Restart Word.
If the problem affects only one document, step 4 is the best first fix. If it affects all documents, steps 1, 3, 5, 7, and 8 are the most relevant.
References:
- Office files may not save if Files On-Demand is enabled
- Open a document after a file corruption error | Microsoft Support
- How to troubleshoot problems that occur when you start or use Word | Microsoft Support
- Word does not save changes or you receive an error message in an Office program after you install Adobe Acrobat 7.0 | Microsoft Support
- cannot save due to a file permission error in WORD - Microsoft Q&A