Getting this error when starting. Interestingly, I can still get in the options menu if I move the error window away. :)
Thanks for the feedback, I was worried about that. Seems to be related to running in windowed fullscreen. I've disabled it from the options menu, but I guess it still can set itself to this mode at first start. I'll get a fix for this asap!
Edit: I've fixed it and re-building the demo now for upload. In the meantime, there is an un-elegant way around this by changing your local settings file found here:
Find these lines:
And change them to:
(if PreferredFullscreenMode isn't set to 1, leave it, also you can set them to 2 if you prefer windowed mode)
You shouldn't need to do this again, the graphics settings in-game will do all the work.