Hey! we are a solution for a dupe item problems? (in 1.8.9) the problem comes from sponge because in solo the problem does not exist 
i need help.
Make an issue about it on their github with all the information you can, including version. Github Be sure to actually look for your issue first, someone else may have reported it.
It’s been six months that I seek a solution to this problem but the worries of sponge comes well as solo i does have this probleme,
the concern does not appear in the server logs as it is detected as an item to throw earth. Sorry for my bad english
Update to 1.10.2, it is fixed.
my serveur is on 1.8.9 
the concern has no solution in 1.8.9?
Update to 1.10.2 as I am no longer supporting 1.8.9.
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