Toad 12.0.0.61 Execute button disabled

Hi, I have recently ungrade to Toad 12.0.0.61 ( was on Toad 10.x). I have a lot package and stored procedure scripts saved as text file (.txt). Now when I open them in the new version of Toad, the Execute button is disabled. If I re-saved the file with extention “.sql”, then the Execute button is enabled. This was never a problem with the old versions. All the existing scripts are checked in source control. Re-saving them as “.sql” files is a lot work. Has anyone come across this problem?

Any help would be much appreciated.

Thanks