I built an explorer. I put the lights on and set everything where I wanted and tested it in game, all good. Then I added my other equipment and now the game crashes when I spawn it in game. All it says is "Game Error. Please reboot or restart game." All the parts I used I have used with no issues before. The parts that seem to be crashing it are the k9 cage and window bars I have installed. If I remove those it loads in game without an issue. Ive used both of those parts before with no problem. Any ideas of things to try would be great!

How high is the poly count on the cage/bars and the vehicle itself? Is it significant (hundreds of thousands or millions of polys) or lightweight? ( a few hundred to a couple of thousand)

Remember the total number of polys is important... So the fact that those 2 extras are crashing it, and it's not when they aren't added, probably means (as you already worked out) that it's the extra's at fault... But Poly count is important and even with a sweet GPU the game engine itself has a shelf limit of rendered polys at any one time.

 

Also, could the problem be related to vehicles.meta? Did you add the required extra flags in that properly?

<requiredExtras>EXTRA_6 EXTRA_7 EXTRA_8</requiredExtras> etc