holding or wearing (optifine) emissive items will cause the 3d book to render completely black. (i'm forced to use optifine for reasons)

Edit: this does not happen when holding a knowledge book

(note, there is no reason to use optifine anymore. not even for fresh animations)

Can you verify that this still happens with ETF? I don't think I'll look into this if its only Optifine(as it has been 100% replaced and surpassed at this point, modern packs don't work with Optifine anymore).