As per previous report in which the steps is provided.
I have posted a video so you can visually see the problem that I am experiencing. There is a ghost cube in the game. I do not know if all of the monsters is the same thing or not. However, these ghosts the player can not kill them but they can kill you. When I exited the game and came back the ghost disappeared but was still there on the cube that I could not kill.
https://www.youtube.com/watch?v=K0cPoXJasuQ&feature=youtu.be
In the video, I try to replicate the issue and this time I was unsuccessful but you can see the problem right off the bat as it was captured on video so you know that I am having this problem.
PV
Just edit the original issue.