Yeah that mod is probably to blame, I'll check it later to see if the bug is something wrong with BeamLR or that mod. The covet shouldn't allow you to remove the body that's probably why the UI got bugged, I'll also check it later. As for career files yeah zip the whole BeamLR folder and upload it. That way I can copy it into a userfolder and get the same game state you have, makes it much easier to debug. Start the game, cause the issue, close the game. Then create an issue report on github making sure to attach log files, screenshots, etc. If you don't want to create a github account do it here but you'll have to upload your log files somewhere else.
Thanks I'll check these when I have the time. By the way I forgot to mention the log file you posted doesn't help unfortunately because there's so many lines that get spammed about FFB for some reason, that the log file reaches the 15000 entry limit before you used a covet. Last lines I can see about a vehicle is a legran. So if you can try starting the game, get the issue to happen and close the game. As quick as you can but don't ALT+F4 do it like you normally would. That way hopefully the log file won't hit the entry limit before the issue happens.
the issue fixed itself somehow lol, i can now sell the parts normally like you would, also i already sold the covet so i cant do that, and about the d-series, im just gonna change the engine