What Makes A Good Submission/The Models Resource
Contents
The Model
Textures
Does it have all of the textures included? Sometimes model editors only copy the texture that is immediately applied to the mesh. Make sure to get all of them, even if the textures aren't copied when exported.
Texture Format
The Models Resource only allows textures to be in .PNG format. It doesn't allow any other format. Make sure that textures are in the .PNG format.