Verify Netherite is Disabled in Your World
Check Your Inventory and Crafting
When the mod is active, netherite items will not appear in the creative inventory or be craftable through normal survival means. Open your crafting menu and search for "netherite" — you should see no results.
Test Ancient Debris
Mine ancient debris from the Nether as you normally would. When you smelt it in a furnace, it will produce netherite scrap as usual. However, when you attempt to combine netherite scrap with gold ingots at a crafting table to create netherite ingots, the recipe will not work.
Confirm the Smithing Template is Disabled
Look for the netherite upgrade smithing template in the creative inventory — it will not be available. This means even if you somehow obtained netherite ingots through commands, you cannot use them to upgrade diamond gear to netherite tier.
Verify Diamond Gear Remains
Diamond tools, armor, and weapons function normally and remain the highest tier of gear available through standard survival gameplay. This is your endgame equipment tier with the mod installed.