QtCreator 3.4.0: No full code model support neither with build-in nor with clang code model

[sliver1982]

I have a cmake based project under windows wich is parsed perfectly by qtcreator 3.2.1. All symbols can be found, all include files, etc.
After updating to newer versions of qtcreator building wihtout problems is still perfectly possible but navigating all c++ symbols in the project as before is not.
I tried the build-in code model as well as the new clang code model. Both fail on finding all files and symbols.
Clang finds more include files but shows less color highlighting.