Installed Office 365 on M3 Powerbook running MacOS Tahoe - verification screen freezes on launch

Question

I installed Office 365 on Apple M3 laptop running macOS Tahoe 26.4. Launched Word after install and the verification window and the app freezes with incomplete appearance. Is there a way to fix this?

Answer 1

Try a clean reinstall of Office for Mac and remove its data folders before reinstalling, as corrupted or incompatible app data can cause Office apps to freeze on launch during verification.

Follow these steps:

1. Quit all Office apps

• Make sure Word, Excel, PowerPoint, Outlook, and OneNote are all closed.

2. Uninstall Office apps

• Open Finder → Applications.
• Use Command + click to select all Microsoft 365 for Mac apps (Word, Excel, PowerPoint, Outlook, OneNote).
• Ctrl+click the selected apps and choose Move to Trash.

3. Remove Office data folders

• In Finder, on the menu bar select Go → Go to Folder….
• Go to: ~/Library/Containers/
• Move to Trash the folders starting with:
  • com.microsoft.Word
  • com.microsoft.Excel
  • com.microsoft.Powerpoint
  • com.microsoft.Outlook
  • com.microsoft.OneNote
• Go back to the Library folder and open Group Containers.
• If present, move these to Trash:
  • UBF8T346G9.ms
  • UBF8T346G9.Office

4. Empty Trash and restart macOS

• Empty the Trash.
• Restart the Mac to clear any locked files or cached state that might be causing the freeze.

5. Reinstall Microsoft 365 for Mac

• Sign in with the Microsoft account that owns the subscription at the Microsoft account services page (as in the referenced steps).
• Download and reinstall the Office apps.
• After installation, launch Word and complete the sign-in/verification again.

If the installer itself ever fails to launch or appears stuck, use the additional guidance from the Mac install article:

• Ensure the download completes fully (around 1.5 GB).
• If the .pkg installer will not launch or appears corrupted, move it from Downloads to the desktop and try again; if still failing, delete it, empty Trash, and redownload using Safari from the Office sign-in page.
• If macOS reports an “unidentified developer” or “Install Failed” error, follow the steps in the article to update macOS and reopen the installer.

If, after a full removal and reinstall, the verification window still freezes, check the “Fixes or workarounds for recent Office installation or activation issues” Mac section referenced in the Mac article for any emerging issues specific to newer macOS releases.

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References:

• What to try if you can't install or activate Office for Mac
• Microsoft Office apps for Mac quit unexpectedly - Microsoft Q&A