I have a Unity project with about 18 scenes that are called in seqeunce as levels. Overnight scenes have started to go "bad", as in Unity opens but displays Untitled next to the project name, the editor Project tab is populated correctly but the Hierarchy tab is blank. The Mac spinning wheel of death just keeps spinning and spinning.
This is quite troubling as I'm very near completion and would like to release in the very near future but not with only about a 4th of the levels. :)
Pertanent info?
I have uninstalled and reinstalled 2.6,
MacMini with Snow Leopard,
Sprite Manager2 and Ez Gui in use,
Unity 2.6 (upgrading to unity3 made it incompatible with everyone else so I can't use that)
I will guess that you have installed Unity 3 and opened your scenes,made with Unity 2.6, with it? Right?
Unfortunately, scenes once opened in Unity 3 will never again work with Unity 2.6...
Yes I know, that sucks...but there is no tool that will convert your scene from 3.0 back to 2.6.
I will guess another thing, when your scenes were converted into 3.0 (with Unity 3.0) you returned to Unity 2.6 and you opened them with it? Right? With this act, you have destroyed them...If it makes you feel any better, you are neither the first nor the last to whom it happened.
Tip for the future: You should make a backup when you are passing over to another version.