Using NuclearCraft's "hardcore containers" radiation mechanics, I get random crashes every so often that seem to point to an issue with how it interacts with your backpacks.

https://pastebin.com/sYHp1KzM

I've opened an issue (tomdodd4598/NuclearCraft#606) on the NuclearCraft side and am awaiting a response, but figured I should open one here as well as it may be more obvious to you from the crash log what could be happening.

• forge-1.12.2-14.23.5.2838
• NuclearCraft-2.18k-1.12.2
• WearableBackpacks-1.12.2-3.1.4

Copy-pasting comments from the other issue:

@turbodiesel4598

I think this is a Wearable Backpacks bug - it should not be null-pointering when NC asks for the capability.

It's happening because the tile returns this, which feeds a null world to this, which then causes a null-pointer here ;)

@copygirl

You're right. Heck, I even noted that over a year ago.

I think the crash only occurs from loot backpacks that have been dropped by entities that spawned with them. So another option to fix this would be to disable the "Spawn Naturally" option in the entity settings.

No worries, at least it’s known about :)