0. ALWAYS PROVIDE INFORMATION ABOUT MODLOADER (Fabric / Forge) AND MOD VERSION (For Example 1.19.2-8.2.10)
   Minecraft Ver:1.20.1
   Forge 47.1.0 - (47.1.30)

1. Describe the bug
   Upgraded server today from Forge 47.1.0 to 47.1.30 also backpack mod from last version 3 to 4
   Backpacks currently on my char are fine no issues, I have many backpacks in chests and scattered around full of items these are all missing this includes the mod upgrades in a chest I had as well.
   Yes like a moron this time I forgot to backup the world folder before upgrade but as it was just a link to latest forge ver and the backpack upgrade I didn't see the point...don't laugh!
   I did read a previous issue about missing backpacks and there is someway to restore this but it does not say how?
   I had rolled back the forge version and no change, Any ideas would be helpfull.

2. Write steps to reproduce the bug

3. What is expected behaviour

4. Screenshots (If applicable)

An update on this issue. So everything placed and stored in over-world spawn area is gone for good however anything 2k blocks out of spawn if fine and has its contents intact also anything in the Nether is fine. So it's a pain I lost a lot of stuff but not as bad as it could of been.
Question.... is it possible for future update to make it possible that if you name a backpack it would create a id file for it and contents remain listed inside and would make it as safe as placing a chest down?

Ah that sucks as that means I have lost many thousands of items as had a lot of full backpacks.. Scattered all over the world.

Unfortuntely, backpacks can be restored only if lost while being on player back. There's no way to restore those backpacks

seems like a good idea