The screenshots along with the step-by-step of what you were doing was very helpful, thank you.
The log file does confirm that the preferences database is broken. In order to fix this, we'll want to have you create a new preferences database, but we would also like to get a copy of your current preferences database, as it may help us improve how errors like this are handled in the future.
First, follow the steps in this document to backup your preferences:
https://camerabits.freshdesk.com/support/solutions/articles/48000341456-backing-up-your-preferences-and-transferring-them-to-anotherThen, quit Photo Mechanic.
Then, open a Finder window, click on the 'Go' menu in the menu bar, choose 'Go To Folder...' and then paste the following in the text field that appears:
~/Library/Preferences/ and then look for a folder called 'com.camerabits.PhotoMechanic'
Rename this folder. I typically do this by adding the date to the end of the folder name; for example: 'com.camerabits.PhotoMechanic-2025-05-15'
Then, right-click on this folder and choose 'Compress 'com.camerabits.PhotoMechanic...''. This will create a new Zip file.
Take that zip file and send it to us. It will contain any data that is saved in the program, so I would recommend sending it to support@camerabits.com as opposed to posting it here publicly.
Then, start up Photo Mechanic. You should now be able to modify the contents of the Metadata Template and have it hold. Once you try that, then go to preferences and load the file that you created after following the steps in the link above.
Your preferences should be restored and the preferences database should be re-built.