Check in your "mesh" file that you have converted, that the textures have been written in on conversion. Tech antimodule for eg.
sometimes they are missed for some reason and you end up with this;
You can just type them in and save.
Also make sure you have put the texture files in the texture folder of your mod.
"Vertcies check sum" error
Haven't run into that 1 before. At a guess, perhaps you have a polygon with 5 sides or more.