Fatal error (28730)

I made my game without any problem till one day I saw this error :
http://mobin127.persiangig.com/untitled221.PNG

I use unity 3.4 … I reinstalled my unity then I opened … but still give me this error… and when I open other projects it work perfectly , but when I want to opened my project give me this error… what should I do?

Create a new project, and simply copy all your assets and scenes into the new project folder. That might just work. I’ve had a corrupt project file before.

Also try opening one of your other scenes, not the last loaded scene in the project. That might determine if its a problem with the scene or the project file itself.