Designer 2 won't open or save files

[B·Ware]

MacOS 13.3.1 Designer 2 won't open files from inside the app using Open. Double-clicking and 

open with in Finder opens files, but then they won't save.

[MikeTO]

Hi, what do you mean by won't open? Does the Open file window let you choose a document? What happens after you click the Open button? Does it do nothing, crash, close without crashing, or something else?

Can you create a new blank document, save it, close it, and re-open it? i.e., is it just certain documents that won't open?

You also say that you can't save files that you open by double clicking. Again, what happens when you try to save, does nothing happen, does it crash, etc. What if you try using Save As?

Do you have File > Save History with Document selected?

Where are you opening and saving files from?

[walt.farrell]

@MikeTO: I see that the OP has several topics open, probably all related. This other one may further explain what's happening: