I noticed that the drying rack and the item shelf both seem to share the same recipe (three wood slabs in a horizontal line). I was trying to make the rack, but it only lets me make the shelf. Is there a way to choose what the recipe makes, or could it be a problem with the multiplayer server I'm on?

I also noticed that crackers (from Campanion, two wheat side by side) are uncraftable. There's a shapeless recipe for wheat flour from Create that uses two wheat, and that one takes priority over crackers. The wheat flour recipe seems to have been modified by Almost Unified (Unified: Yes, Had Duplicates: No) so I'm not sure if that's important.

Update your pack, this was fixed a couple updates ago.