Starting crash - pure virtual function call from exit crash after installing blood dragon.

So I've been playing this the last few days & am on level 4. It's a fresh install & the game was giving me a "Pure Virtual Function" call whenever I tried to exit the game... wasn't interfering with game play or causing any damage to anything that I could tell.
However last night I installed Far Cry 3: Blood Dragon through Ubisoft's UPlay (a.k.a. UPlayWithHeavyDRM) & I couldn't get that game to run without letting it do all it's install scripts. I'm not sure what all it did for installs... I know it did a directx install (like every other game in the last 20 years...) & I believe it installed some visual c++ runtimes.
After it started running I quit & went back to Pillars Of Eternity only to find that the game now gives the Pure Virtual Function crashing error on start during the opening credit videos & refuses to start.
My googling has only returned one answer that's really related to "Pure Virtual Function" that seems likely... & it's a mircosoft statement saying it's intended behaviour & that the code is written wrong & to re-write the code to remove the virtual call. (Reference: https://support.microsoft.com/en-us/kb/125749 )
I'm wondering if anyone else has the error because at this point it's now stopping me from playing the game at all.
As troubleshooting steps for myself I ran installs of the Visual C++ x86 runtime that was posted on the Obsidian forums as one of the dependencies (md5 of installer: 6402438591b548121f54b0706a2c6423) as well as ran an install of directx & did a cold boot of the machine (not really a troubleshooting step... just turned the computer off for a few hours to save some power).

I'm going to bet that it's actually a Windows registry problem, probably some library missing or not registered correctly. You say it's a clean install, but did you cleanly UNinstall and clean the registry before re-installing? If not, I would try that.

Hmmm.... GOG didn't tell me of this reply. I'll try that though honestly I don't have high hopes for just a registry change. It sounds Visual C++ Runtime specific & re-installing that should have updated all the registry entries & dlls.

Well no one else had any other suggestions on Steam or here so I did try a re-install. I'm no longer getting a pure virtual function call error. Now it just crashes with an "AppCrash" windows generated error message. Bit better... I guess. :-/

So I win my bet? :p

For the AppCrash, that could be absolutely anything. First of all you need to be certain not to install the game to a protected folder structure, because Windows and security suites don't like that one bit. You should also take preventative measures, like closing down all unnecessary applications while playing games, or at least while troubleshooting -- other software can often be the cause of 'AppCrash' faults. Now is the time for some detective work on your part. If you need further help, you're going to have to furnish system details, including where the game is installed to.

You win 25% I think.....

As for the rest of it.. I think I have it figured... a bit more testing but it seems to be working off hand (30 second trial so far). Even though I did a complete uninstall, deleting all files & registry entries I could find (following http://forums.obsidian.net/topic/68591-uninstalling-does-not-uninstall-completely/ ) apparently it doesn't actually remove EVERYTHING. There appears to be something left over.. somewhere.
I did a second reinstall tonight only this time I changed the path... even though I do use UAC & the original install was not in a folder that requires elevation. In fact it's not on a drive that requires elevation & even so I elevated to the administrator/administrator account & it still crashed. However the new install works... & as far as I can tell the only thing different is the path.
Before it was installed in e:\SteamLibrary\blahblahblah & now it's installed to e:\games\... & it now loads to the title screen & exits with out a crash. I have to restore my saved game & run it for awhile but off hand that's looking solved.


---Edit---

Well it still crashes on exit... the same app crash but for now I can load & play my saved game. I had it running for about an hour.
Probably whatever was left over that was causing the problems on the old path... whatever & where ever it is.
I'm also guessing the stupidly long paths aren't helping. The new path is about 20 characters shorter I think.. but I see there's files with paths several directories deeper as well.

Any further ideas are welcome.