0. ALWAYS PROVIDE INFORMATION ABOUT MODLOADER (Fabric / Forge) AND MOD VERSION (For Example 1.19.2-8.2.10)

1. Describe the bug
   While playing on my own dedicated server (both client and server has the same mod version - travelersbackpack-fabric-1.21.1-10.1.15) when I have some backpack equipped while having other backpack in my inventory and try to unequip this backpack by opening it and pressing "unequip" icon, I receive the backpack to my hand slot, but cannot access it, neither via simple right-click or placing it on the ground.
   Fabric version - 0.16.9

2. Write steps to reproduce the bug
   Connect to dedicated server with this mod installed
   Get 2 backpacks (with some items and upgrades)
   Equip one of them
   Access other backpack while having the first one equipped
   Try switching the backpacks

3. What is expected behaviour
   Expected behaviour is to access the backpack or be able to switch it again, instead I am getting kicked, my game crashes (not the server tho) or I am finally able to place the backpack after several attempts while also trying throwing it and picking up again, although last time I did that to recover backpack it reset (cleared all items and upgrades) to zero state.

4. Screenshots (If applicable)

Is it happening with every backpack? or just specific ones you use?
The best way to check that would be to craft new backpack and use it.
If it's happening with every backpack please provide mod list if you use any additional mods.

From what I can see the console log screenshot is from the moment when you place the backpack on the ground and trying to access it. Does the console say something when you try to open backpack from hand?

Did you update the mod from older version? or anything specific you've done before issue started to happen?

I didn't check every possible backpack, although it happend with every backpack I have tried, like lapis lazuli dropped by mob or quartz crafted by myself. The most important part is that it doesn't occur after crafting a new backpack and using it, but after taking it off and then trying to use it.

List of loaded mods in attachment.

I didn't update the mod, and since the dedicated server has only 2 weeks, I could say the issue were there from the beginning.

mods.txt.txt

Is it happening on singleplayer too?

Could you pack all the mods from mods folder to archieve and send it to me?