DVD Maker - Pro Creator Burn

I already have this installed on my Mac Computer and until a couple of days ago had no issues.

However I can no longer use this as after I go into the App it requires my Apple Id and password (something I haven’t had to do previously)

after which I get an error message saying it is in the wrong format. Today I have spent most of the day talking to Apple who tell me that I need to contact the supplier for advice. It was suggested that I uninstall the App and reinstall but I am reluctant to do this as I do not want to have to pay again or indeed lose all of the years of film I have on there and the current project.