http://pastebin.com/fJkV94Zx

I am part of the Official All the Mods server and our players keep getting the same crash in roughly the same place. No idea why though? It affects users with and without Optifine and with and without FoamFix.

It seems to be a bookshelf render issue?

Interesting, I will look into the further and let you know.

Any update on this, it is still happening daily.

It seems this issue is caused by trying to render a null/invalid tcon pickaxe. In the situation described by this crash only the vanilla code is being executed here.

@Baughn in your situation it's the com.rwtema.extrautils2.items.ItemBlockPlantable@1e3581 which is causing the issue. As far as I can tell, Bookshelf and CCL have nothing to do with this crash. If you would like to help confirm if that is true, and if this is a reproducable error, can you try reproducing it without Bookshelf installed? If that fixes it, try again but this time remove CCL and add bookshelf back.

Hmm. Don't think I can do that, sorry; I wouldn't be able to remove those without thoroughly corrupting the world state.

Bookshelf is at the top of the non-Mojang stack trace, which is why I reported it here.

http://pastebin.com/2LKsswda

Here's another one. Looks pretty similar, but it's a different item.

As noted by the TCon devs, this issue is with Mekanism and not Bookshelf.