Unity: 4.2.1f4
Win 7/64 bit
NGui Standard
I upgraded my 2.2.6c project to 2.7 without any issues. Everything was working pretty much the same after the upgrade with the exception of a few depth sorting issues which I deferred until I had upgraded to 3.x.
Upgraded to 3.08f3 with the instructions - creating a new scene, deleting ngui, importing ngui, fixed the compile errors, and then ran the upgrade package to install the editor scripts.
After this I tried to bring up my core menu scene which contains most of the menus in a deactivated state, and Unity crashes. Unfortunately I don't have the log anymore as I was able to get the scene to come up successfully later (more on this below).
I know the call died in UIAtlas:Upgrade on the line: UnityEditor.AssetDatabase.SaveAssets();
I started binary searching and have found that if I delete all the atlases (your four example ones plus the two custom ones I had made), the scene comes up properly after that, albeit with broken references to the removed atlases of course.
I would very much like to not have to rebuild and re-reference these atlases - so I guess my next step will be to repeat until I know which atlas(s) is potentially causing the problem and then only delete that atlas to minimize rebuilding.
I'm guessing there is just no enough repro info here to really have any idea what is going on. Just a shot in the dark..
