Hi,

Was playing with the train ramps, and got a crash on a dedicated server, with the following log. (2.1.14, updated mods)
I was testing my train network with the ramps, and jumps/recovery (a bit tricky to understand especially when everything explodes on landing :P)

Hope it helps finding the issue/fix.

11276.656 Info AppManager.cpp:316: Saving finished
11573.292 Info AppManager.cpp:315: Saving to _autosave13 (non-blocking).
11573.391 Info AsyncScenarioSaver.cpp:177: Saving process PID: 27108
11576.955 Info ChildProcessAgent.cpp:61: Child 27108 exited with return value 0
11576.955 Info AppManager.cpp:316: Saving finished
11873.676 Info AppManager.cpp:315: Saving to _autosave14 (non-blocking).
11873.778 Info AsyncScenarioSaver.cpp:177: Saving process PID: 27361
11877.305 Info ChildProcessAgent.cpp:61: Child 27361 exited with return value 0
11877.306 Info AppManager.cpp:316: Saving finished
12119.192 Error MainLoop.cpp:1503: Exception at tick 85853414: The mod Renai Transportation (2.3.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event RenaiTransportation::on_nth_tick(1)
Trying to change direction of automatic train moving on a path.
stack traceback:
        [C]: in function '__newindex'
        __RenaiTransportation__/script/trains/on_tick.lua:387: in function 'handle_trains'
        __RenaiTransportation__/script/event/on_tick.lua:11: in function <__RenaiTransportation__/script/event/on_tick.lua:9>
12119.192 Error ServerMultiplayerManager.cpp:85: MultiplayerManager failed: "The mod Renai Transportation (2.3.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event RenaiTransportation::on_nth_tick(1)
Trying to change direction of automatic train moving on a path.
stack traceback:
        [C]: in function '__newindex'
        __RenaiTransportation__/script/trains/on_tick.lua:387: in function 'handle_trains'
        __RenaiTransportation__/script/event/on_tick.lua:11: in function <__RenaiTransportation__/script/event/on_tick.lua:9>"
12119.192 Info ServerMultiplayerManager.cpp:809: updateTick(85853414) changing state from(InGame) to(Failed)
12119.197 Quitting: multiplayer error.
12119.197 Info GlobalContext.cpp:760: Deleting active scenario.
12121.235 Info ServerMultiplayerManager.cpp:147: Quitting multiplayer connection.
12121.235 Info ServerMultiplayerManager.cpp:809: updateTick(18446744073709551615) changing state from(Failed) to(Closed)
12121.235 Info ServerMultiplayerManager.cpp:167: Deleting active scenario (global = true).
12121.237 Info HttpSharedState.cpp:57: Downloading https://multiplayer.factorio.com/remove-game/1172026
12121.403 Info UDPSocket.cpp:238: Closing socket
12121.403 Info UDPSocket.cpp:268: Socket closed
12121.403 Info UDPSocket.cpp:238: Closing socket
12122.398 Info UDPSocket.cpp:238: Closing socket
12122.398 Info UDPSocket.cpp:268: Socket closed
12122.398 Goodbye