Some mods have been around for *very* long and have been broken long before the 0.30 T-Series was removed. The truck itself is totally fine, it's just those mods that are wrecked.
Disable all the 0.30 T-Series mods to see what happens. This seems to be problem on your side, it works as usual on mine.
They’re still good I checked them out today and they are still in good shape when I downloaded the T-series pre-remaster from another post. --- Post updated --- I found a sketchy link on another website , I just searched up “0.30 Beamng drive” and clicked on the first result, I highly recommend to download at your own risk as it could be hiding malicious software but I’m not sure because I never tried doing so and probably won’t in the long run.
Why not just use the files from here? https://www.beamng.com/threads/0-30-gavril-t-series-and-trailers.95616/
It still does. Closest it is to being broken is that spawning it first breaks some of the trailer's textures, since they partly use the same folder names.