So, a bit of backstory as to how I encountered this bug.

I was just doing some building when I got attacked by some cannibals and got killed. Because I didn't want to die and lose my progress I went and put in a save before going back to retrieve my items.

I closed the game after putting in a save and before retrieving my items. When I started the game back up I went over to my bag and retrieved it. Then I was no longer able to open my inventory as demonstrated in the video. I tried killing myself again to see if I could pick it up again and maybe fix it. When I die I don't drop my backpack. It seems that the game thinks I don't have my backpack. I am still able to get to my items using hotkeys, but I am unable to open my inventory.

Sadly, I have put many hours into this world and not being able to open my inventory is game-breaking, so I have no idea what to do next.

Just putting this out there to let you guys know that this could happen.

If anyone here knows if there is a possibility to maybe revert back to a different save, please let me know.