Error when compiling Minecraft Forge mod with ItemGroup.MATERIALS

[HardRoma]

Hello everyone,

I'm encountering an issue while trying to compile my Minecraft Forge mod. I'm using Minecraft Forge version '1.16.5-36.2.34', and I've defined an item in my mod using ItemGroup.MATERIALS. However, during compilation, I'm getting the following error:

D:\programming\minecraft mods\Study\forge-1.16.5-36.2.34\src\main\java\com\hr29\study\items\MaterialItem.java:10: error: cannot find symbol
super(new Item.Properties().group(ItemGroup.MATERIALS));
symbol: variable MATERIALS
location: class net.minecraft.item.ItemGroup

I've already checked my build.gradle and it's configured to use '1.16.5-36.2.34'. Is there anything specific that I should be doing to resolve this error?

Any help or suggestions would be greatly appreciated. Thank you in advance.

[Luis_ST]

I don't currently have a mod in 1.16.5 but I would say due to the error the ItemGroup.MATERIALS no longer exists, use your IDE to check this.

In addition you can take a look at the Items class for vanilla examples, you should then be able to fix the error.