Try deleting all of the files in the '
..\Divine Divinity\Run\Dynamic' folder.
This folder is used as a cache for the game. Files are created / copied there from the save game folder when you load, and written / copied from that folder when you save a game. The files will be re-created as required the next time you start Divinity. If there was a corrupt file in that folder, deleting the files should fix the problem.
If that doesn't work, try starting a new game and see if the problem persists. Use
iZakaroN's SaveEditor to increase your level and constitution, and run to Ars Magicana to buy some scorpion traps from Tingalf. If the new game works, but the latest save does not, there may be a problem in the saved game folder itself. If neither work, it may be a problem with Divinity, in which case re-installing might help.
Zip or otherwise backup your saved games folder to another location first, just in case. Then un-install, re-boot, shut down all non essential programs (especially anti-virus), re-install the game. Re-boot, shut down all non essential programs, install the patch, re-boot, shut down all non essential programs, start the game. This procedure is a bit over-cautious, but the best way to avoid install problems.
Troubleshooting Tips (& manual install procedure) 
