Ok, I solved my problem.

If I set the effect in the MDL I have to set some material values as well.
After having them set both shaders are working fine together.

Meteor Mess 3D:
https://www.meteormess.de
Facebook:
https://www.facebook.com/MeteorMess3D
Twitter:
http://www.twitter.com/MeteorMess3D
Discord:
https://discord.gg/naJJgdMQDV