Quote from SurfaAdd -dx80 to the launch options and it should fix the problem. It seems as they broke the direct 9 version of the viewports.
yea thanks, I saw this on the steam forums as well.. luckily the thing still compiles in the current state, at least I'm able to work in -dx80 mode and compile in the current "broken" mode ;o
hopefully the full fix will arrive this week...