When I'm trying to import Obj/Fbx files from Maya to Houdini I get errors i simply do not understand. Hopfully someone here can help me out.

When i try to import a Fbx file it says:

Error: Could not inititlize FbxImporter (Unexpected file type).

And with OBj's see the attachment

I tried different Export Setting and reinstalled the programs. Currently running Houdini 15.5.480 and Maya 2016 SP6 with NC Licences

Hope that anyone here can help me with that.

Your problem looks like some sort of configuration thing to me. I'd first save a copy of your environment variables and then try removing from the environment variable values, anything that mentions Houdini, Python or Maya.

Apparently i do not have any environment files for that. Maybe that's the problem?

No, it doesn't need to be environment files.