Well. I'm trying to be more precise. I use the 3d2gs plugin for 3dstudiomax to make the WMP file. Now, I've made a city with (for example) 5 palaces.
So, exported and imported in WED and it seem ok (no error).
Unfortunatly I've missed a palace, so reopened the project in 3dstudiomax and built it. Now, if I export ALL the palaces again into WED, works very fine (no error), but if I try to export only the new palace and added into WED as a prefab i got this error....


I hope that it was a clear explanation and sorry for my English!