Black screen on startup

Hey, I preordered Sins Rebellion and I downloaded the beta 2 from Steam, but after I installed it and I tried to play it, there was no intro video, just the sound. And after the intro video was finished, there was just a black screen with the menu music. The in game cursor was there but that's it.

Also, if I alt+tab away, I can see the top left corner of the menu screen briefly before it switches tabs.

I'd appreciate any advice on how to fix this. I've already tried reinstalling the game.