Could be a number of reasons that are not necessarily related to our game. It is possible of course, but I handle most incoming support issues personally and a freeze like the one you are describing is a first, at least for the full game. We do not get many support issues related to the demo.
That does not mean we can't help in figuring out what the cause is or look for a solution. You can also try running our support tool
http://www.larian.com/hotfixes/supporttool/LPC_Divinity2.exe and sending the report.xml it generates to support[at]larian.com together with a link to this thread, although I am not sure this will work on a demo installation.
