Describe the bug
Serious exploit!
Ender backpack has an exploit which duplicates all items in it!
your wonderful plugin just RUINED THE GAME on my server :((

To Reproduce
I am not exactly sure how to reproduce it because other player did it and just told me about it which made me quite mad as many items were duplicated

Version info
It was 2020.0.4

Without details, even if this is a legitimate bug, I can't do anything about it.

However, I find it unlikely that such a glitch would be possible for the ender backpack, assuming the exploiters do not have the ability to start/stop the server (and even then).