Since the PC Experimental 1.16 Update 3 - Version 1.15.154535 (Released on 11.02.2022) I have multiple error messages (7500 lines) in my server .log even without any mod.

Function: 'Error'
Stack trace:
scripts/1_Core/proto\endebug.c:92
scripts/4_World/entities\firearms\weapon_base.c:355
SCRIPT    (E): 
Weapon.OnStoreLoad Flaregun<bdfc3a60> trying to set muzzle index 4 while it only has 1 muzzles!
Class:      'Flaregun'
Entity id:2973693
}

It seems to generate one message like this for each weapon on the map.

If I delete my "storage_1" folder the messages don't appear the first time I launch the server but they come back as soon as I restart the server.
Note that I entirely refreshed my mpmission folder (no old or custom code inside)