I've already posted this on AA's issue tracker, so I hope you don't mind me just referencing that issue over there :) Ellpeck/ActuallyAdditions#351 Basically, when rendering the lamp from Actually Additions in bit form via the Enchiridion mod's book editor, it crashes the client

Does it also crash when scrolling though the C&B Creative Tab?

Let me check, just a second

No, it doesn't. I also searched for them in the C&B tab, and they did appear.

That is odd, If one gui crashed rendering the item, I'd expect it to crash in there as well.

And it's not that bits in general are crashing, it's just the lamps

Right, but if the lamp bits crash in Gui A, why not Gui B?

No idea, maybe it's how Enchiridion handles rendering?

Doubtful, have the lamps changed at all? Maybe the book has a bit displaying in it that is "no longer valid?" or have no updates or changes been made to the pack since the "book" was made?

I updated FTBUtils and Lib, then downgraded them again because they were being buggy, I also installed and uninstalled Optifine, and I don't have any bits in the book.

Ok.. so it shouldn't be a bad bit item... This is quite unusual.

Yeah, the only thing I can think of is the item selector has a bad bit in it somehow?

Seems like the only real explanation, since the C&B tab which has all the "real bits" isn't showing any issues, but why would it contain items that aren't in the creative tab?

Exactly, it should only be able to pull from the item registry at most, preferably creative tabs.

I installed Actually Additions, and Enchiridion - I was unable to reproduce the crash however, I scrolled though the entire item list in the editor and it never crashed... there was a lot of items to say the least...

I'm not sure what the deal is here.

I can't reproduce the issue, are you able to reproduce this consistently? What about in a fresh instance?

Any other details to help reproduce the issue would be helpful.