Hi - I got this crash while arranging the tubes sort of "backwards" with a red cable

The mod UPS Friendly Nixie Tubes (0.2.9) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event UPSFriendlyNixieTubeDisplay::on_script_trigger_effect (ID 170)
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:227: attempt to index local 'display' (a nil value)
stack traceback:
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:227: in function 'invalidate_cache'
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:235: in function 'invalidate_cache'
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:235: in function 'invalidate_cache'
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:235: in function 'invalidate_cache'
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:283: in function 'configure_nixie_tube'
UPSFriendlyNixieTubeDisplay/scripts/nixie_tube.lua:500: in function 'handler'
core/lualib/event_handler.lua:72: in function <core/lualib/event_handler.lua:70>