The mod has a giant red box that says: This giant red box means the mod is outdated, and no longer works 100% correctly.
This is a known issue with the current version of WBIMP and had been reported several times for the past couple months. A temporary "fix" to this would be to move the "fullsize" folder away from the mod itself (effectively remove any Grand Marshal add-ons and configs).
--- Post updated --- There. Can everyone now stop talking about the missing textures ? They are fixed for the time being.