GPG Mail Upgrader fails to activate GPG Mail

In some cases the GPG Mail Upgrader is launched after upgrading to macOS 12.3 but fails to complete and following re-try attempts fail as well.

The reason for this problem is that GPG Mail Upgrader fails to close Mail which is necessary to complete the upgrade. In most cases this happens, because there's still a dialog presented in macOS Mail which is trying to inform you that an incompatible plug-in has been disabled.

To resolve this problem

1. Close Mail app
   
2. If the GPG Mail Upgrader is still running, press retry
   2a. If it's no longer running, reboot macOS and it will launch shortly after reboot

The GPG Mail Upgrader doesn't start automatically after reboot

To manually launch the GPG Mail Upgrader please follow these steps:

1. Open Finder
   
2. Press CMD + SHIFT + G
   
3. Type /Library/Application Support/GPGTools and press Enter
   
4. Find GPG Mail Upgrader.app and double click on it (not to be mistaken with GPG Suite Updater)
   
5. Make sure Mail is closed
   
6. Press Upgrade
   
7. Launch Mail and check if Mail › Settings › GPG Mail is present

The upgrader doesn't appear to launch even when started manually

1. Open Terminal (easiest to find via Spotlight, the loupe icon in menu bar)
   
2. Type /Library/Application\ Support/GPGTools/GPG\ Mail\ Upgrader.app/Contents/MacOS/GPG\ Mail\ Upgrader -FromInstaller YES -Force YES and press enter
   
3. Make sure Mail is closed
   
4. Press Upgrade
   
5. Launch Mail and check if Mail › Settings › GPG Mail is present

The upgrader still fails

If the upgrade still fails it is possible that you are running into a macOS permission bug.
For yet unknown reason macOS sometimes applies very restrictive permissions to the GPG Mail plug-in. This is known to happen when re-installing macOS (keeping user data), restoring a backup from TimeMachine or having run the macOS Migration Assistant recently.

Unfortunately this issue can only be fixed by temporarily disabling Apple's System Integrity Protection:

1. Disable System Integrity Protection by following this guide:
   https://developer.apple.com/documentation/security/disabling_and_en...
   
2. Once macOS has rebooted, open Finder
   
3. Press CMD + SHIFT + G
   
4. Enter ~/Library/Application Support/Mail/Plug-ins/Bundles/Library/Mail/Bundles
   
5. Delete GPGMailLoader_6.mailbundle
   
6. Press CMD + SHIFT + G
   
7. Type /Library/Application Support/GPGTools and press Enter
   
8. Find GPG Mail Upgrader.app and double click on it (not to be mistaken with GPG Suite Updater)
   
9. Make sure Mail is closed
   
10. Press Upgrade
    
11. Launch Mail and check if Mail › Settings › GPG Mail is present
    
12. Re-enable System Integrity Protection again (see Apple article from Step 1)

If none of the aforementioned steps work and the GPG Mail Upgrader still fails, please contact us via System Settings > GPG Suite > Contact Support or update your existing discussion if you had created a related one before reading this article.