John Doe says:

Game.log shows that it’s missing files:
‘/vehicle/truck/upgrade/paintjob/freightliner_cascadia2019/test/template.tobj’
‘/automat/aa/.tobj’
‘/vehicle/truck/upgrade/paintjob/freightliner_cascadia2019/test_skin/test_skin.tobj’
/material/ui/accessory/freightliner_cascadia2019/test.mat
/def/vehicle/truck/western.4900/accessory/boxes/shape02.sii
/automat/02/02077f4dbdcda7a5.mat

People really shouldn’t upload mods until they’ve checked them out for themselves. Only armatures do this.

Also has some bad naming conventions implemented; a lot of the parts have the same name copy/pasted for each one, or some random word. Just laziness. And, the airdam for the front bumper doesn’t look like it’s supposed to go along with any of the bumpers. It’s almost as if it’s more of a clipping issue. There are also a few icons missing in the UI panel for some of the parts and a lot of accessory conflict errors.

And, you do not get a lot of accessory slots to customize on this truck, apart from the cab lights and that’s it. So, you’re stuck with whatever set parts the modder decided to give to you, which isn’t much.