Description of the issue:

When right clicking with an Engineer's hammer with the NBT tag multiblockInterdiction with a value of ["IE:Crusher"] (specifically, given by the command /give @p immersiveengineering:hammer{multiblockInterdiction:["IE:Crusher"]} ), the game crashes. I might've gotten the tag usage wrong, but the syntax seems right to me.

Crashlog:

https://gist.github.com/KevinHuang8/5f65cc460e5091985ef7510e9a9580dc

Versions & Modlist

IE 1.16.4-4.1.1-128
Forge 35.1.4

That would be because you set invalid data on the item. Machine names are Resource locations which are all lower case. (Make sure you have valid names)

If you're looking for the crusher I believe the string you want is 'immersiveengineering:multiblock/crusher'

I'll reopen this, IMO setting wrong data there should not cause crashes. It should either do nothing at all or notify the player in chat that the NBT data is wrong.

In 1.12, I thought the string to pass to multiblockInterdiction was the one returned by getUniqueName for MultiblockCrusher, which is still "IE:Crusher". Indeed, if you have the NBT tag {multiblockInterdiction:["IE:Crusher"], the tooltip for the hammer correctly states that it should forbid the crusher, suggesting "IE:Crusher" is the right tag. Not sure what else to pass in ("immersiveengineering:multiblock/crusher" does not work, and the tooltip doesn't have proper localization).

Is the problem that getUniqueName no longer returns a valid resource location?

Ah, nevermind, I was looking at the wrong branch lol no wonder.

The location was "immersiveengineering:multiblocks/crusher"