I had the same issue.
I have the following observations:
- Using the latest build I was able to get back into my script. Archilab and Rhythym are still giving System.IO.FileLoadException.
- I was able to get back into my script after removing all packages from AppData\Roaming\Dynamo\Dynamo Revit\2.0\packages
- I was able to get back into my script after removing the library xml manifest file the libraryViewExtension
But after 2 and 3 you can do nothing with dynamo.