gmcs.exe ERROR

Hi. I’ve got a problem. When I start the Unity and i try to import the packages at the end of importing I am receiving this error message :

Cannot open assembly D:\Zlohy\programy\Editor\Data\MonoCompiler.framework\gmcs.exe.
Internal compiler error. See the console log for more information.

I have tried to reinstall it … i even downloaded it again but nothing could fix it.

Please help.

thx…