I didn't notice something special to do this:
I deleted a zone with red print. At the end there is an underground belt left. And my robots bring me coal from this again and again and again...
It seems that the undeground belt still receive coal while marked as deconstruct.
There is the save of the map: http://kryssemi.fr/factorio/bugDestruct.zip
If you connect to it as player "fochristo" you will see the problem immediatly (tested)
Underground belt deconstruct
Re: Underground belt deconstruct
It looks like every time one of the long-handed inserters takes items from the belt it puts more items into the underground belt (something that isn't supposed to happen).
If you want to get ahold of me I'm almost always on Discord.
Re: Underground belt deconstruct
Thanks for the report.
Fixed for 0.15.12
Fixed for 0.15.12