KeyNotFoundException: The given key was not present in the dictionary.

Questions & Answers
1

this massage is always shown to me , and once I delete the folder “Library” and run the project again it doesn’t show this massage anymore , but if I tried to close unity3d the program stops responding ,so I had to close it from task manager , and once I open the project again , the same massage comes to me
I only have one script in my project untill now and it is a javascript
I tried so many things until now and it couldn’t work

thanks in advance

2

I fixed it by creating a new project in another location and then I deleted the new project’s assets folder and copied the assets folder from my original project … it has been fixed but another error appeared
the new problem is
ApplicationException: Unable to find a suitable compiler