thanks for sharing the FBX. We confirm the loading problem of your 3d model in the Wikitude3dEncoder from the SDK 4.1 release. The loading problem is resolved in the newer version which will be part of the SDK 5.0 release (comming soon).
Besides that we see some problems with your model which shows a file size of ~150MB. The 3d model is far too big to be used within the Wikitude SDK on a mobile devices. We recommend - to export the 3d model as a binary FBX (not ASCII), and - to reduce the size of the textures used (which sum up to ~60MB) by reducing the size of the image files significantly.
(Probably this already resolves the loading problem. So give it another trial.)