If somebody can help me out (again), there was a First Order Troop Transporter 3d model I found a while back; I bring it into XSI to convert to a .msh but I get an error and this is what it says when I try to export it:
Any ideas as to why this message is occurring?

Cheers,
MT

You should make use of ZETools error checking tool to diagnose potential problems in your scene.

Select your model and press "Check Sel" in the Export dialog to test for errors.

I do that, but it comes out blank. No errors were showing in the pop-up window

You need to change the constant shaders to phong or lambert.

How would I do that?

Open the Render Tree and create a new phong or lambert shader and connect it to the material node then reconnect the image node,
or replace the contents of your *.mtl file with this and reimport the obj: