I'm being told there is an Unhandled Exception error and that I cannot use the working.pbb file.

Claims it is already in use

Do you have OneDrive backing up your My Documents folder? If so you probably want to exclude the Wolverine Studios folder from that because if One Drive is backing up the folder at the same time you are playing you could receive an error like this

So far, so good after changing up OneDrive. Thanks for the feedback.

Well....that worked for a bit. Now when I try to create a new league, this message comes back:
An unhandled exception error has occurred: Could not use C:\users\me\documents\wolverine studios\DDSPB19\Leagues\working.pbb; file already in use

I've turned off One Drive to eliminate that possibility.

Is this happening if you exit the program and come back in or just if you were playing one league and then going to the main menu to create another league?

It originally was happening within an existing league but after turning off One Drive there were no issues.
Now I'm attempting to create a new league and the error is back.

One Drive is no longer looking at any directory associated with the game.

And of course 10 minutes after posting this, I tried to create a new league...........worked like a charm so I don't know what to say was happening yesterday