EDIT: It was an issue with the model I downloaded, making a new model from scratch and have not had this issue.
It has been a long time since I modded Mudrunner, I added a rock and added what I thought was a .cdt (following my own guide from 2018) however trying to open the model in the Editor gives me this:
In 3DS Max it looks like this, notice the left side with the Names:
And the AXE Exporter settings for .X:
I used to make a lot custom models willy nilly with ease but for some reason I cannot see what I have done wrong.
I have the model, CTRL+V , copy it, name it "cdt" and click OK, select all, export selected. What am I doing wrong here?