How to Fix the Mace Still Looking Flat After Installing the Pack

Rule Out Pack Order First

A flat mace almost always means another resource pack is winning. Go to Options → Resource Packs and drag Amazing Mace 3D Resource Pack to the top of the Selected list. Any pack that also touches the mace — weapon packs, PvP packs, all-in-one texture overhauls — will override it otherwise. Apply the change, then press F3 + T to reload resources without restarting.

Check for Conflicting Packs

If it is still flat, disable other packs one at a time and reload after each. The moment the mace pops into 3D, you have found the conflict. Keep the two packs from overlapping by leaving the offender disabled, or accept the trade-off if you prefer that pack's other textures.

Confirm the Right Item

Make sure you are actually holding a mace and not a similar-looking weapon from another mod. The pack only replaces the vanilla mace model. If you are on a server, remember that resource packs are client-side: your mace looks 3D to you, but other players only see it if they also have the pack installed. Nothing about the pack changes damage, reach, or any gameplay value — it is purely visual.