Strange model issue ingame

[Maui]

Heya, I recently rigged a Skyrim skeleton and I gave it some nightingale armor too.. now for some reason only the Right side shows me this:

 

Any idea what that could be?

For some reason it's transparent. :S

[Raz0r]

As a non-modeller, it looks like either a shader issue (cull twosided) and/or inverted normals on the mesh.

[Maui]

You saved me, Raz0r. Thank you!