Sometimes when bots places a bulk rail unloader.. or loader, not 100% sure. I managed to get a save that crashes 5 seconds in because a bot places an unloader. In total I got 3 random crashes (same error message), 2 of which only occurred once . After I reloaded my auto-save they didn't happen again. However the 3rd crash always happens when I load my latest save (Right now I can build the loader manually to get rid of that particular crash...).

I've never had any problem with this mod before. I got these 3 crashes in one single day. I have not added any new mods, I haven't done anything new... anywhere, well, sure I got Factorio 0.,18.32.. so kinda recent if you include that I update Factorio, but not day-to-day recent that would cause me to get 3 crashes in one day. So I believe that the bug is some very very very weird edge case.

Here is the error message I get when it crashes.

The mod bulk Rail Loader (1.0.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event railloader:on_robot_built_entity (ID 14)
Expected target_circuit_id for target entities with more than one circuit connector.
stack traceback:
railloader/control.lua:159: in function 'create_entities'
railloader/control.lua:202: in function
railloader/control.lua:195>
(...tail calls...)
stack traceback:
[C]: in function 'connect_neighbour'
railloader/control.lua:159: in function 'create_entities'
railloader/control.lua:202: in function
railloader/control.lua:195>
(...tail calls...)