The problem is not reproduced at the moment. I think the problem is fixed.

Factorio version: 0.17.21
Platform: Windows 7 x64
Mods:
https://mods.factorio.com/mods/MagmaMcFry/Factorissimo2
https://mods.factorio.com/mod/Warehousing
https://mods.factorio.com/mods/Optera/LoaderRedux

Only on client. On host bug not reproduce. Perhaps the client had problems with the Internet ...

Crash host after player (not host) exit from game.
Current game version: 0.17.21
Start game version: 0.17.21
Platform: Windows 10 x64
Mods: Factorissimo2 (version 2.3.1)
Game settings: multiplayer PVP scenario (3 player)

Last Autosave file