How to delete a non-removable polygon that can't even be selected?
The one indicated by the blue arrow is not selected and is not deleted.
![Nonpng.jpeg](//image.easyeda.com/pullimage/YqNpbSswnrnRiBXvCt4vclrDDCNZYugxEsU9tD6d.jpeg)
Firefox
68.0
Linux
EasyEDA
6.4.31