The mod Connection Indicators (0.2.8) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event fluid-connection-indicators::on_tick (ID 0)
...d-connection-indicators__/script/update_fluid_entity.lua:28: bad argument #1 of 2 to 'pairs' (table expected, got nil)
stack traceback:
[C]: in function 'pairs'
...d-connection-indicators__/script/update_fluid_entity.lua:28: in function 'calculate_any_connected'
...d-connection-indicators__/script/update_fluid_entity.lua:115: in function 'update_fluid_entity'
fluid-connection-indicators/control.lua:73: in function 'update_single_entity'
fluid-connection-indicators/control.lua:121: in function 'handle_scheduled_updates'
fluid-connection-indicators/control.lua:209: in function <fluid-connection-indicators/control.lua:204>

I got this Error when I placed a Fluid wagon on a station with 3 Pumps ready to fill the wagon,
The Wagon had no other Locomotives.

I have a save file if you need it.
I am using other mods, i disabled them all, loaded the save again and it still happend.