SkinnedEffect turns to BasicEffect

I know that sombody had already the same Problem, but it’s still not solved. I’ve exported a 3D-Model from blender in fbx format.
My settings in the Content Pipeline are as follows:
Build Action: Build
Importer: Fbx Importer - Mono Game
Default Effect: SkinnedEffect

After I build everything and started the Programm, I got an Exception, because my model’s effect is treated as BasicEffect.

Is there a solution for this Problem?