Backpacks glitching


**I am currently running**
- Modpack Name: Chudtopia
- Java version: 1.12.2
- Operating System: 64-bit

Please include as much information as possible. For the description, assume we have no idea how
mods work, be as detailed as possible and include a step by step reproduction.
**Issue Description**

sometimes when i go into my diamond backpack some items that are in my inventory appear in it and if i try taking stuff out it gitches and moves my other backpack into my hotbar and wont let me take items out

Please provide a *full* log (and crash-report if applicable).
Go to and upload them there, then paste the resulting link here!



btw the repair tablets are not really in the backpack. And it seems to i think only happen when you do it in someone elses claim