Error while running event mining-patch-planner::on_tick (ID 0)
mining-patch-planner/layouts/simple.lua:235: attempt to index local 'center' (a nil value)
stack traceback:
mining-patch-planner/layouts/simple.lua:235: in function 'heuristic'
mining-patch-planner/layouts/simple.lua:274: in function 'placement_attempt'
mining-patch-planner/layouts/simple.lua:399: in function '?'
mining-patch-planner/layouts/base.lua:59: in function 'tick'
mining-patch-planner/control.lua:26: in function <mining-patch-planner/control.lua:16>
642.144 Error ServerMultiplayerManager.cpp:91: MultiplayerManager failed: "The mod Mining patch planner (1.1.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event mining-patch-planner::on_tick (ID 0)
mining-patch-planner/layouts/simple.lua:235: attempt to index local 'center' (a nil value)
stack traceback:
mining-patch-planner/layouts/simple.lua:235: in function 'heuristic'
mining-patch-planner/layouts/simple.lua:274: in function 'placement_attempt'
mining-patch-planner/layouts/simple.lua:399: in function '?'
mining-patch-planner/layouts/base.lua:59: in function 'tick'
mining-patch-planner/control.lua:26: in function <mining-patch-planner/control.lua:16>"
642.144 Info ServerMultiplayerManager.cpp:797: updateTick(7772644) changing state from(InGame) to(Failed)
642.159 Quitting: multiplayer error.
645.180 Info ServerMultiplayerManager.cpp:140: Quitting multiplayer connection.
645.180 Info ServerMultiplayerManager.cpp:797: updateTick(4294967295) changing state from(Failed) to(Closed)
645.181 Info HttpSharedState.cpp:54: Downloading https://multiplayer.factorio.com/remove-game/11850008
645.899 Info UDPSocket.cpp:218: Closing socket
645.899 Info UDPSocket.cpp:248: Socket closed
645.899 Info UDPSocket.cpp:218: Closing socket
646.181 Info UDPSocket.cpp:218: Closing socket
646.181 Info UDPSocket.cpp:248: Socket closed

Thanks for the report but this by itself doesn't really tell me how to fix it.
It would help if you could provide a save file and tell what options you were using.

when use journey scenarios

Check if it is nil then do nothing

Released an update that tweaks some values. Could you tell me if it still crashes?
If it still does I'll use your fix suggestion.