Try /dev in the start up properties of scrap mechanic in steam & on the host PC.
Switch to that window as the game loads and that could point you towards more info of the problem.

and give us logs, you can DM it to me on discord (@theredbuilder)

Sorry, it's -dev not /dev

You get there by right clicking Scrap mechanic in the steam library and clicking properties then there's start up options on the right, put -dev in that box.

Switch to the dev terminal whenever with "Alt + Tab" or windows key to show it clickable in the windows task bar. Probably switch after selecting the Crashlander custom game.

Get to log files by right clicking Scrap mechanic in the steam library and clicking
"Browse local files" in there you'll see log files click / send the one/s associated with the day it crashed.

From the machine it crashed on. :)

Appreciate the responses.

Unfortunately, my friend already deleted the map and we just started from scratch.
I'm unable to re-create the crash with creative but will definitely enable -dev just in case this happens again in our run.

Will keep you guys posted for any updates