Go to Steam -> Library -> Right click on Sins Rebellion -> Properties -> Local Files -> Verify integrity of game cache.
This updates any missing or damaged files from your game. For me the update was only partially done when i went from 1.3 to 1.4, but after doing this it worked flawless.
Hope this helps fix your shit. If you want me to explain exactly what to do in Dutch just send me a PM. I'm confident though that you will get there using the steps I explained here.