All my chests show up with inventory not generated, as well as it doesn't let me open any of the chests, it was working fine previously

The "Inventory isn't generated" is technically an issue with the Jade plug-in rather than with Lootr.

If the containers won't open, however, that means that there is a more significant error.

I will need a copy of your latest.log file, either from your server (if multi-player) or your single-player.

I also need to know which version of Lootr you are running, which version of Minecraft, and which version of mod loader (NeoForge, Forge or Fabric) you are running.

i have the same problem but it the chest is invisable aswell this is the log:
POI data mismatch: never registered at BlockPos{x=-236, y=90, z=-221}

@mkp303 Please open a new issue. The chest being invisible is likely unrelated. Please include the full log, as well as information about what version of Minecraft, what mod loader, and which version of Lootr you're using.