I'm a bit late to the party here, but I had the exact same problem and thought I'd register and share how it was resolved for me.
The problem turned out to be a corrupt setup.xml (empty file, size 0) located in the same folder as save files. On my computer that folder is below: C:\Users\USERNAME\AppData\Roaming\Frontwing
When I deleted it, it was recreated with default values and the game started up normally.