In Agiledashboard plugin, in Planning-v2

Given User story A with 1 child Task Alpha
and given User story B without children
When I drag Task Alpha and drop it into B
and I drag it from B and drop it from A
and repeat the above twice
Then there will be a javascript error from the dragular library: Uncaught TypeError: Cannot read property 'parentNode' of null

After this error is triggered, it can cause problems with drag&drop and "ngRepeat:dupes" errors.
It happens on 'cancel' event in dragular, 'null' here is the dom element that was dragged (the backlog item).
I think it might be caused by the fact that the 'drop into' mechanism removes the item that was dragged from the dom.