I was playing with a bunch of guys on a modded server and we had backpacks on, and the admin switched us to creative for a sec so we could get a look at the area, and we noticed after going back to survival that our backpack inventories had been cleared out. I assume this was going into creative mode that caused it, but it could have also been going to survival from creative mode (or both). We also have 'unbalanced mode' on in case that might have anything to do with it.

Can't reproduce.

Seems to happen randomly

Video: https://youtu.be/jWHQFzt8Gy8

Possibly related to MinecraftForge/MinecraftForge#4580?

Can't fix if it's a forge bug.

we can actually fix this... smh