This sounds like an error in your dependancies (shared resources between games).
(1) Try disabling hardware PhysX:
It might be worth turning off hardware PhysX ... If you right-click on your Windows desktop and select "NVIDIA control panel", you should have an option for "Set multi-GPU and PhysX configuration" under "3D Settings". From here, under "PhysX Settings" set "Processor:" to "CPU" and click "Apply".
(2) Try reinstalling all dependancies: Find the folder "Steam\steamapps\common\divinity ii - dragon knight saga\support" in your windows program files folder ("Program Files" on 32 bit OS, "Program Files (x86)" on 64-bit OS)
Uninstall then reinstall every installer you find under this "Support" folder.
See my posts on the following thread for more details:
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=433378#Post433378Hope this helps, and good luck!