Just spent a couple hours chasing down a glitch with a script that worked fine with Mojave. It was choking when it tried to add an attachment to a new mail message. ‘Mail Couldn’t get file ‘. I tried all the recommended security/privacy settings, adding ‘Script Menu’ to ‘full disk access’ and so on. None of it made a difference. Was it because I wasn’t using a file reference? Nope, I was passing an alias.
Finally in desperation, I Decided to look at Mail’s dictionary for ‘attachment’ and there was the problem. Dictionary now uses posix path for the file name of the attachment but using an HFS path alias innMojave worked like a charm. So adding ‘posix path of’ to my HFS file path seems to have fixed it.
Sure would be nice if there was some documentation of ‘what’s new’ in Catalina’s Applescript.