Modpack Version

1.20.2.zip

Describe your issue.

A few times now I've noticed that my inventory is reverted to an older variant between sessions. This has regularly resulted in items- some valuable- being deleted. In some cases, entire sessions of progress is lost due to my inventory being reset. I don't have any clue what's causing it. There isn't necessarily a common crash occurring, although this most recent time occurred after I was timed out due to my internet dropping. I wish I had something more helpful to offer to figure out the cause, but so far the occurrences haven't been very consistent.

I play on a small server between friends, though the server has 16g of RAM. I am by far the most active on the server, and have been the only one to notice the issue so far.

Crash Report

No response

Latest Log

No response

Have you modified the modpack?

Yes

User Modifications

Distant Horizons was included by the server host on the server files, and I added it to my pack to help.

Did the issue happen in singleplayer or on a server?

Server

Discord Username

foxdogist

seems to have been a corruption of backpack items/player data. can this issue be closed since it is not a modpack issue?

I have begun to experience this issue myself on our small private server.
-Items disappearing from backpacks in Sophisticated Backpacks while the items still show up in the player save data. Two occurrences in the last 3 days. Once while backpack was on the hotbar slot 0 and the second while it was in the Back slot. (Specific examples: Dominion wand, Feeding upgrade, Advanced Magnet Upgrade, Just Dire Things Fluid Canister containing 4 buckets worth of lava.)
-Skills panels: experience, spent and available points reset to 0 at the same time as the items go missing.

I did a name change this weekend and did a full character reset on the server. I had assumed the first reverting was a bug due to this. Now that it has occurred again with no changes save the daily server restart.

Crash Report
-N/A

Latest Log
-N/A

Have you modified the modpack?
-No

User Modifications
-N/A

Did the issue happen in singleplayer or on a server?
Server

Discord Username
-TheMadHatter

I have begun to experience this issue myself on our small private server. -Items disappearing from backpacks in Sophisticated Backpacks while the items still show up in the player save data. Two occurrences in the last 3 days. Once while backpack was on the hotbar slot 0 and the second while it was in the Back slot. (Specific examples: Dominion wand, Feeding upgrade, Advanced Magnet Upgrade, Just Dire Things Fluid Canister containing 4 buckets worth of lava.) -Skills panels: experience, spent and available points reset to 0 at the same time as the items go missing.

I did a name change this weekend and did a full character reset on the server. I had assumed the first reverting was a bug due to this. Now that it has occurred again with no changes save the daily server restart.

An important question, is the server using online mode? name changes should have no affect if online-mode is enabled due to the uuid being constant.

offline mode (even for paid accounts on an offline server) use character name as the player uuid and many mods store uuids for access and ownership.

Additionally, the server log from when you logged off and when the server was stopped (or the first save after you logged off) could be important as it may indicate an issue saving your player data, such as storing storage inside storage inside storage exceeding the NBT limit, preventing saves (or corrupting the saved data)

are you noticing the issue when another user comes online or when you come online when other users are on? the only thing i can think that might cause this what feels like randomly is duplicated uuids of backpacks which shouldnt happen during normal play. ids are regenerated if 2 backpacks are carried with the same id or if 2 players have a backpack with the same id (as the chance for a uuid collision is effectively 1 in longer than the amount of time the earth has been around and would occur at backpack generation)

are you noticing the issue when another user comes online or when you come online when other users are on? the only thing i can think that might cause this what feels like randomly is duplicated uuids of backpacks which shouldnt happen during normal play. ids are regenerated if 2 backpacks are carried with the same id or if 2 players have a backpack with the same id (as the chance for a uuid collision is effectively 1 in longer than the amount of time the earth has been around and would occur at backpack generation)

The thing I noticed myself that stoped causing the issue was using a sophisticated backpack with the inception upgrade that was also enchanted with soulbound. I haven't seen the issue resurface since. I think something relating to how soulbound keeps items in a players inventory- especially when matched with stacking backpacks, is the likely culprit.

Online mode: Yes

Logs for the 5-12-25 added. Last date with said items.

2025-05-12-3.log.gz
2025-05-12-1.log.gz
2025-05-12-2.log.gz

This mornings server restart logs:

2025-05-13-1.log.gz

Additional finds: Inconsistency between player save data and Sophisticated Backpacks save data for the same bag as of today. Took me a big to dig through both and figure out what I was looking for. Player save data shows the upgrades still in the mentioned backpack, but SB does not.
EDIT: Digging further it shows a reference to the Infinity Ham Relic that was used in the Feeding slot. This item is also missing from the backpack inventory.

--.DAT files uploaded for reference.
Downloads.zip

In-game image of said backpack, opened from player hotbar:

Unable to upload .DAT files here for reference

Can you please zip the .DAT files you are trying to upload and upload the resulting ZIP files?

Both issues occured with no other players online.

I only had the one backpack and 3 chests with sophisticated backpack upgrades on them, though more than a few exist with other players. As such stacking should not have been an issue.

After looking through the backpack immediately following my discovery I have found duplicate items i had deposited into my storage. Exact stats in a pair of boots and a sword. Hard to get with the variety of Apotheosis mods. I am beginning to suspect that it rolled back my character state for some reason. The skills being reset along with the missing backpack items. Quest markers in the Craftoria quest screen remain though as do learned recipes. So it was just my character and their personal inventory and skills.

Edit: More duplicates found. No inventory or skill resets as of this mornings server restart.