Hi!! And sorry for the issue. You're the second person to report the same error, but I haven't been able to reproduce it to create a fix. Can you tell me exactly what steps you followed? Even let me know what the program logs say, here’s the path: C:\Users\[Your username]\AppData\Roaming\Godot\app_userdata\Beast Breeder\logs.
Again, sorry for the trouble, but I need to reproduce it to find and squash this stupid bug.
Thanks!!