I'm hyped for Space Age, buuuut: This error happens directly after migration from latest 1.1.x, when either loading an existing save, or trying to create a new game.
I'll investigate whether I can fix it, e.g. by purging the AppData folder, and keep you updated. But it shouldn't happen, so I guess it's Bug hunting time again

EDIT: The German text means "The system can't find the file specified". Added for clarity.