Namespces not found though they are listet in references

Hello Everyone,

I’m stuck at this problem for a view days and can’t find a solution. I installed two versions of Unity, one beeing 32 bit so I can use the Vuforia Framework, one 64 bit for all non AR related projects. Now when I start the AR project in the 32 Bit version I can enter playmode and everything works fine. As soon as I edit one of the scripts, it’ll give me serval namespace errors related to the UnityEditor.UI or the Eventsystem. I installed Visual Studio to exclude that this is a Mono related problem but it seems the project uses the wrong references. In my solution there are two projects listet, one ending with .CSharp containing just a view references like UnityEditor and UnityEngine. The other one’s ending with .CSharp.Editor containing the other references. Adding the UnityEngine.UI.dll manualy to the .CSharp references seems to solve the issues for a second, but when building the project I get the same errors back again.

Would be really great if anyone could help me, BIG THANKS IN ADVANCE !

Best regards, Lorenz

It had something todo with corrupt registry entries and that unity tried to use the wrong dlls.