I got a crash while removing a single, unconnected medium power pole that was in a Factorissimo2 level 1 factory. The pole was connected by a green wire to an inserter and through that to combinators, tanks, and fluid pumps. The crash report follows:

Error while running event ShowUnconnected::on_player_mined_entity (ID 65)
Neighbours can't be used on this entity.
stack traceback:
ShowUnconnected/control.lua:136: in function 'amount_pole_connections'
ShowUnconnected/control.lua:167: in function 'place_to_neighbours'
ShowUnconnected/control.lua:180: in function <ShowUnconnected/control.lua:177>
stack traceback:
[C]: in function 'index'
__ShowUnconnected/control.lua:136: in function 'amount_pole_connections'
ShowUnconnected/control.lua:167: in function 'place_to_neighbours'
ShowUnconnected/control.lua:180: in function <ShowUnconnected/control.lua:177>

Thanks for report, I'll try to reproduce and fix it.

Please try to reproduce this crash, I cannot.

I just tried, but could not. When I pick up the pole now, I just get an alert printed to the console that says "not electric-pole: [inserter][inserter]" The bracketed object seems to be whatever it was connected to by circuit wire.

Thanks, this was helpful. Now I can understand how this bug comes.