4731.567 Error MainLoop.cpp:1283: Exception at tick 40288648: The mod Schall Tank Woodcutting (1.1.1) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event SchallTankWoodcutting::on_entity_damaged (ID 100)
Item stack count has to be a positive integer.
stack traceback:
[C]: in function 'spill_item_stack'
SchallTankWoodcutting/control.lua:57: in function 'car_harvest'
SchallTankWoodcutting/control.lua:73: in function <SchallTankWoodcutting/control.lua:72>
4731.567 Error ServerMultiplayerManager.cpp:91: MultiplayerManager failed: "The mod Schall Tank Woodcutting (1.1.1) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event SchallTankWoodcutting::on_entity_damaged (ID 100)
Item stack count has to be a positive integer.
stack traceback:
[C]: in function 'spill_item_stack'
SchallTankWoodcutting/control.lua:57: in function 'car_harvest'
SchallTankWoodcutting/control.lua:73: in function <SchallTankWoodcutting/control.lua:72>"
4731.567 Info ServerMultiplayerManager.cpp:797: updateTick(40288648) changing state from(InGame) to(Failed)
4731.578 Quitting: multiplayer error.
4733.026 Info ServerMultiplayerManager.cpp:140: Quitting multiplayer connection.
4733.026 Info ServerMultiplayerManager.cpp:797: updateTick(4294967295) changing state from(Failed) to(Closed)
4733.028 Info UDPSocket.cpp:218: Closing socket
4733.028 Info UDPSocket.cpp:248: Socket closed
4733.028 Info UDPSocket.cpp:218: Closing socket
4733.647 Info UDPSocket.cpp:218: Closing socket
4733.647 Info UDPSocket.cpp:248: Socket closed
4733.656 Goodbye

Server Mods
- The most popular
Factorio Version
- latest Stable

Same error still occurs, though I believe my on_entity_damaged (ID X) was 101, not 100. Still, it still happens.

Should be fixed in my fork of this mod (see here for more details)!

Just uploaded 1.1.2 & 2.0.0 updates, hope the above bug can be dealt with them.