If you encounter a bug, tell me what you are doing at that time will normal enough for me to figuring out the issue. Sometimes, I may need to know what mod config you have changed, and what other mods you are using. If you can provide me the crash log, it will help me a lots.

Main menu → Host Game → right hand side, Manage World →
1. Duplicate World (as a backup)
2. Open World Folder → Master → server_log → crash log is normally at the bottom
(if you can't find it, simply tell me what you are doing at that time. Normally, it will be enough for me to figure out the issue)

Then, you can rollback to latest normal playing game. And you can choose to disable this mod and keep playing. If you disable the mod, the chest will become normal size and the item in excess will drop onto the ground. You are not suppose to lose any items because of disabling the mod.

Note that, if you choose to disable the mod, the chest will still be un-upgraded since the upgrade data has lost. You will have to upgrade again. Or rollback to the game when this mod is still enabling.

I will keep focusing the comment here after the mod has update for about half a hour so that I can response to the bug I did not figure out during testing. You are appreciated to tell me the bug at your earliest convenient. So that I can response fast to avoid more player encountering same issue.

If possible, you can "Duplicate World" as a testing server. You can test whether problem solve if you default the mod config. You can test whether the problem solved by disabling some mods. Tell me what you conclude will help me a lots.