First pass.dll error that I get whenever I open unity or press play

This is from the editorlog :

  • starting compile Library/ScriptAssemblies/Assembly - CSharp - first pass.dll
  • Finished compile Library/ScriptAssemblies/Assembly - CSharp - first pass.dll Internal compiler error. See the console log for more information. Exit code from compiler was: -1073741800

Please help :(

it seems that you use a language feature that is not supported by this version of C# compiler of mono. unity 3 will upgrade it's mono compiler and all new features will be available. i can not find this compiler error code but please check your console and tell me that what is the error there that it can not compile your code.