Hi...
With FBX models you will normally have an accompanying .FBM folder with the textures in it. Do you have the textures in this folder? The folder should have the same name as the FBX model. So an Avatar.FBX will have a folder called Avatar.FBM. You can try creating the folder if you don't have one and place the textures in it and see if 3DXchange recognises it.
One other thing to check is that the textures are in a format 3DXchange can recognise like JPG or PNG. Formats like DDS will not be recognised.
Of course the final option is to apply the textures manually within 3DXchange itself. If you only have a few textures this will often be easier than trying to find the cause of the missing texture problem.
Peter
Forum Administrator
www.reallusion.com