This is consistently reproducible. When the host closes the game (only by hitting x), the other connected games crash and require force quitting. I think this might be due to attempting to save?
[16:06:38 TRACE game] setGameMode( 'titleScreenGameMode (0)' ) [16:06:38 TRACE game] CleanupReturningToTitle() [16:06:38 DEBUG Cooking Skill] beforeSave
Minimal output before crash ^

@hawkfalcon I can't reproduce this. Does it happen if you temporarily remove all mods?

I've confirmed this to be caused by Skip Intro - without any mods the other player's game returns to the title menu fine, and with Skip Intro as the only mod they crash.