Grasshopper Error after plug-in installation

Hi there,

after loading a few new plug-ins into the component folder, grasshopper lost all its toolbar and commands. Starting GH following error appears:

Of course I delated all the plug-ins again, but nothing changed.
I uninstalled rhino6 and downloaded it again, without any success.

Also I removed all files of the plugs-ins also in the appdata /roaming folder, but the error still appears.
Would be happy about any suggestions!

PS: Using Rhino6 in Parallels Windows10