Be warned about this, it hasn’t gone away. Check you licensing after updating to Mac OS 11.3.
I just installed the Mac OS update 11.3. I’m running Xojo 2020R2.1. Once again the licensing is lost following the OS update. What’s new here is that if I open a .xojo_project file it does no automatically save as a binary file without warning allowing me to continue working with the .xojo_project file extension that is really a binary file. You could do a lot of damage that way in source code control.
Now if I make changes I am allowed to go on working. But when I go to save the change the only option is as a binary file.