I'll play with paths to make this happen less frequently.
I may be wrong about what I said. There could be a script causing issues with MP but I won't know until someone tells me. If you don't mind, have a run with it again after I release the bugfixes and more vehicles. I would like to hear the specifics of when, how and what crashes the game down to the actions done by each player.
Also I am on AMD myself, though with an NVIDIA GPU and I can say that it is really hardware dependent. I've tried Em4 on Intel systems that ran poorly and I have no clue what specific thing makes the game choose to not run well.
It's been over a year and I still have not found pictures of the rear of that tiller, or the sides I need to model it. I am hoping those pictures surface someday, but I am at the mercy of the private collection owners who release pictures at a snail's pace.
There is no cure for this, it's just how Em4 works. Montana mod will have the same thing with the rotator lightbar equipped units in that mod. Sadly it's this or nothing.
I cannot replicate the issue.
Even if it works fine for me, I will still try to find the cause for your crashes. I will alter some code and see if it changes anything for others.