Open MS Word on an iMac after installing MS365

Try these steps in order on the iMac to get Word and files opening again:

1. Check if Word is crashing or freezing when opening documents
   If Word stops responding when a document is opened, follow this sequence:
   • Clear Auto Recovery files:
     1. In Finder, on the Go menu, select Home.
     2. Open Documents > Microsoft User Data > Office Autorecovery.
     3. Move the contents of Office Autorecovery to the Desktop (do not delete yet).
     4. Start Word and try opening a file again.
2. Install the latest Office updates
   • Open any Office app (Word, Excel, etc.).
   • On the Help menu, select Check for Updates.
   • Select Automatically keep Microsoft apps up to date.
   • Select Update and install all available updates.
   • Restart Word and try opening files again.
3. If Word hangs only on specific documents
   Follow the additional Word for Mac steps:
   • Check the document name:
     • In Finder, rename the file so it contains only letters/numbers (remove symbols such as % or other special characters), then try opening it again.
   • Reset Word preferences:
     1. Exit all Office apps.
     2. In Finder, on the Go menu, select Home.
     3. Open Library (hold OPTION while clicking Go if Library is hidden).
     4. Open Preferences.
     5. Find com.microsoft.word.plist and move it to the Desktop.
     6. Start Word and test. If Word works, leave the file in Trash; if not, restore it and continue.
     7. Still in Preferences, open Microsoft and move com.microsoft.word.prefs.plist to the Desktop.
     8. Start Word and test again.
4. Reset the Normal template
   • Exit all Office apps.
   • In Finder, Go > Home.
   • Open Library > Application Support > Microsoft > Office > User Templates.
   • Move the file named Normal to the Desktop.
   • Start Word and test opening files. If this resolves the issue, delete the old Normal file.
5. If Word shows an error that the file type is blocked or won’t open older files
   • Use Word’s Recover Text option:
     1. Open Word.
     2. On the File menu, select Open.
     3. Select the document once.
     4. In the Open dropdown, choose Recover Text, then select Open and confirm any warning.
     5. Once opened, go to File > Save As and choose Word Document (.docx).
   • Alternatively, upload the file to OneDrive and let it convert:
     1. In a browser, sign in to OneDrive.
     2. Select Upload and choose the file.
     3. After upload, select the file and wait for the conversion message.
     4. Select File > Save as > Download a copy and save it to the Mac.
6. If Word or other Office apps will not start at all after installing Microsoft 365
   • Completely remove and reinstall Office for Mac (per the Q&A guidance):
     1. Quit all Office apps.
     2. In Finder, open Applications.
     3. Command+click each Microsoft 365 app (Word, Excel, PowerPoint, Outlook, OneNote).
     4. Ctrl+click and choose Move to Trash.
     5. In Finder, select Go > Go to Folder and enter ~/Library/Containers/.
     6. Move to Trash any folders starting with:
        • com.microsoft.Word
        • com.microsoft.Excel
        • com.microsoft.Powerpoint
        • com.microsoft.Outlook
        • com.microsoft.OneNote
     7. Go back to Library > Group Containers and move these (if present) to Trash:
        • UBF8T346G9.ms
        • UBF8T346G9.Office
     8. Sign in to the Microsoft account at https://account.microsoft.com/services and reinstall the Office apps.

If, after all of these steps, specific documents still cannot be opened, they may be corrupted and a backup or recreation of those documents may be required.

References:

• Word for Mac document stops responding when you try to open a document
• Microsoft Office apps for Mac quit unexpectedly - Microsoft Q&A
• we are sorry, but word has run into an error that is preventing it from working correctly. Word will need to be closed as a result. Would you like us to repair now? - Microsoft Q&A