I don't use any other mods that add new items or blocks, just vanilla items. Aside from that I only use Optifine, Appleskin, AmbientSounds 5 and Sound Physics Remastered.

The tooltips just do not show up at all, doesn't matter what item it is, none show up. Help?

It will crack with Optifine.
idk why this happen.

Thanks for the report, this has been fixed in the latest version of Iceberg/Legendary Tooltips.