Just to give some more instructions, as if you were me, it took a few tries to get this right.
After you download 3.0.3, from https://github.com/M...theater-x64.zip
Extract to folder.
Then the first time you run Theater it will create the default folders in that location.
The config folder will now exist and you can edit the system.xml file and change AutoUpdate to False (Before you run Theater again or it will upgrade)
to set autoupdate to false:
Thanks to the other posters for getting me running again.