A word of warning: I played Wastelands 2 and Book of unwritten Tales 2 and then I had the great idea to take a look at Dragonfall DC because I was curious about the changed UI and such things. After installing and running Dragonfall DC my other Unity Engine games started to crash with the most hated access violation 0xc0000005 error. All of them ... every Unity Engine game besides Dragonfall is crashing now. So thanks HBS, you are dumbasses.
A word of warning to everybody else. Make a restore point or something before killing your other games, because uninstalling Dragonfall DC doesn't help.

Oh, i thought from your title that because you had a bad experience with shadowrun dragonfall dc, and because it was made on unity you were no longer looking foward on playing other unity games. xD

Thanks for the warning. I have to check if expeditions: conquistador works fine or not.

I can play any Unity engine games after Dragonfall DC, not sure why you have problems, no changes to the system outside game are made as far I am aware of. In fact this is the first time I heard such thing. However I know that java updates can sometimes kill stabillity of OS to the point that even uninstall won't help and format/reinstall of OS is needed.

It was definitely the installation of DF DC which made problems with my other unity games. Played Wasteland 2, installed DF DC at a point and took a look at the changes in the DC, restarted Wasteland 2 and it crashed after a few minutes from that point on and this was true for two other unity engine games also. Nothing else changed in that time period. After none of the solutions offered by various forum threads (if you take a look you will find quite a bunch of threads about the access violation 0xc0000005 error) I restored an earlier restore point. So my suggestion: create a restore point before you install DF DC and check your unity games afterwards. It takes less then 10 minutes until they crash midgame without any explanation. Games that crashed for me: Wasteland 2, Book of unwritten Tales 2 and Endless Legend.

So, I repeat: create an restore point. ;) It doesn't hurt and makes your life much easier.
I could post my system specs now, but I don't think it depends upon it. Maybe the OS makes a difference: Win7 x64 in my case.

I'm not sure how the DC program itself could cause that kind of widespread problem with another engine, especially since that sort of conflict would usually result in a crash on startup/load, not after a while spent playing. It's possible that the installer (provided by GoG/Steam/whoever) is doing something that it shouldn't, though even in that case the result would be unusual.

I know there was an update for Windows released on the 1st of October. Is it possible that it was installed at around the same time as the DC? (Depending on your update settings, it nay have happened in the background without you noticing since I don't remember it requiring a restart.)

Hmm. I have both Shadowrun games, Endless Legend and Wasteland 2 on my Steam account. They work just fine and I play them frequently one after another. It's possible something got messed up in the OS after the installation. It's very hard to say for certain.

are viruses out of the question?

That's a good question, since I have regular Shadowrun, Dragonfall Director's Cut, Wasteland 2 and a few other titles and they run like a charm on Steam.