There was a permissions glitch at some point in the MacOS installer and some permissions were set so they can’t be overwritten. Try going to “Applications” and delete the existing Alcorn McBride folder before running the update installer.
What about my product files?
All your product files should be stored in the Documents/My Product Files path if you’ve created any product files, but worth checking that folder to make sure you’ve got everything from the stock Product Files folder also.
Keep in mind all the core ones will be re-added when the installer runs again.