Wikitude

3d-Model does not appear

Hi, I'm a newbie at wikitude.

I have the following problem with wikitude studio:

I can preview the text, button and picture at wikitude app. But cannot preview 3d models.

I exported the 3d Model as .fbx. and convert it to .wt3 with wikitude encoder.

I want to create a new project and upload the wt3 3d-file. Wikitude shows a blank cube at design screen but at the preview screen I can not see anything. 

 

Can anybody help?

Bastian