AppleScript failed to retrieve the script's source code

Has anyone seen this message: AppleScript failed to retrieve the script’s source code

I have a script that I’ve been working on for weeks that has been running flawlessly. I used yesterday. I tried to open it this morning and got that message. In SD I tried to see previous version via the revert menu but all of them had that same message.

Any suggestions?

Recover damaged script worked. After I opened it I tried to compile and I got a compile error. I had one of the script libraries open in SD with debugging on and the compile error was that it didn’t seem to belong to appleScript. Could that be related? I turned off debugging and saved and it compiled just fine.