Dank Null Version: 1.12.2-1.7.91 (Latest release on curseforge)
p455w0rds Lib Version: 1.12.2-2.3.161
Forge Version: 14.23.5.2854

Steps To Reproduce:

1. Craft a /dank/null MK VI
2. Put any amount of cobblestone in it.
3. Shift-click it all out of the danknull
4. Throw the danknull on the ground
5. Pick it back up
6. Open it, and notice that there's suddenly more cobblestone in the danknull.

Was this tested on Single Player or Server (or Both)? Both

Was this tested with just Dank Null installed, if not what is the minimal set of mods to cause the issue?

Yes, but only in singleplayer.

Demo

+1 been an issue for years…

In 1.12.2 Direwolf20 pack is the same bug but I found out that you don't have to drop it actually you can put it in your inventory then back to your hotbar and dupes the items

In 1.12.2 Direwolf20 pack is the same bug but I found out that you don't have to drop it actually you can put it in your inventory then back to your hotbar and dupes the items

can you reproduce that

After installing the latest beta version, it seems to be fixed.

I'll still leave this open though, because most people will be getting the latest release installed with the launcher.