The title says it all, I have a project created in unity 4.2.1 and windows 8, it worked solidly, then I upgraded to 8.1 and 4.2.2 and tried to import a new asset and it crashed, so I reinstalled 4.2.1 on 8.1 and now it won’t even open the project when it tries to import all the assets, my game is a 2d game and never had any issues until now, any suggestions?
Thanks all.
I have exactly the same problems. Damn Windows 8.1. I can’t even run any games from Steam since updating to this blasted Version. 
Found this in another thread. Hope this helps! 
Thanks for that will try this when I get home, another one that I had found that worked was going through the command prompt.
I too have crash at ultrabook with Intel HD 4000 and NVIDIA Geforce GT 620M.
How i fixed it :
Works great, until you use the scroll wheel. It likes to think that “scroll down” and “close program” are one and the same. I’m strongly debating murdering 8.1 in its sleep. Not sure if I have everything I need to upgrade to 7.
As for the force dx11 thing, that had zero effect under 8.1
Since this only affects the asset store, I doubt Unity will even try to look at it as a problem since it only costs the asset devs money. Since I usually spend about $100 a week on assets and since this error, it has dropped to $0. I’m sure many others are doing the same. It’s a shame Unity could give a rats hairy behind when this is such a serious and becoming common problem now that 8.1 was released on the 17th.
Working in 8.1 and Unity is just running fine. Maybe you have to update your Drivers. I tried playin a game and it seems as if Windows is no longer taking care of your graphics Settings, so my nvidia Manager was set to 3D and my games were like 8-bit Colors. Had to upgrade the Driver and turn 3D off, that did it for me for graphics Problems. Just try upgrading it.
I too had crashing issues beginning with Unity3D v4.2 and above. None of the typical solutions (DX/GL modes, DEP/UAC, etc.) solved my crashes. After MUCH investigation, I located the issue:
Seriously. Corrupt fonts.
I discovered it referenced on the Unity-engine HearthStone’s forum from a user named Omrakos. That particular post references one particular font. These fonts were not the same.
My solution was to backup my “c:/windows/fonts” folder, delete all of the fonts that windows would allow, then copy them back a section at a time until Unity crashed again.
In fact, Unity never crashed again, but windows refused to install a handful of the fonts. I suspect these were the corrupt ones.
As I’d searched for weeks without finding a solution, I thought I would share this one with the community.
Hope it helps!
Be well, always!
I had exactly same problem on freshly installed Windows 8.1 and Unity 4.2.2, running on original Surface Pro. Following solution helped:
Change the target so Unity.exe gets opened in d3d11 mode:
YOUR_PATH\Unity.exe -force-d3d11
Good luck.
This was my very first time using Unity, I used the “-force-d3d11” change and now it works!
Thanks!
“-force-opengl” works too.
So it may be a good idea to have both of them on your desktop, just in case.
Thanks for info, I’m going to add it as well!
after re installing unity because the 8.1 update has screwed me, i was searching through the folders and ran into a file located in the temp folder in my 86 program files not the project documents. A file named unityfilelocked i deleted the entire folder and replaced it with a empty folder named temp now unity runs perfect every time even with the 8.1 update.
Really, I never thought of doing that, thanks for the tip, I just changed the compatibility from windows 8 to nothing, I am going to find this folder and remove it and just add a folder called temp?
Tried this and it still doesn’t work.
I ran CCCleaner and it seemed to work so far. Maybe some temp files not getting deleted causing issues?
TY.
This solved my problem with Intel HD 4000.
this worked for me
Sorry to bumb a somewhat old thread.
I’m using Intel Graphics HD 4000, and Unity used to crash frequently, but the “-force-d3d11” fix worked great for me.Thanks a lot!