Just to make sure we understand what the issue is: once a process (like MIDI Translator Pro) tries to execute AppleScript, MacOS asks the user if that’s allowed. If the user denies that request, there is no way in MacOS to revert that decision. Consequently, that process is blocked from executing AppleScript forever.
Now here, it seems that MacOS has blocked AppleScript for MIDI Translator Pro on Chris’ computer. The only way we know for persuading MacOS to allow MT Pro to execute AppleScript is to directly edit the internal MacOS database containing these permissions, as outlined in this thread:
https://forum.bome.com/t/mt-pro-problem-executing-apple-script/5737/12
On our computers, we have been able to confirm that the described approach works.