AlexIIL

After talking on IRC it turns out that a large issue was world.setBlockState(pos, (IBlockState) AGE, world.getBlockState(pos).getValue(AGE).intValue() + 1); when it should have been world.setBlockState(pos, getDefaultState().withProperty(AGE, currentMeta + 1));

Do you get the exact same error? What may help would be to put a new line between each function call (so Minecraft.getMinecraft().getRenderItem().getItemModelMesher().register(item, 0, new ModelResourceLocation(Asolin.MODID + ":" + item.getUnlocalizedName().substring(5), "inventory")); would become: Minecraft.getMinecraft() .getRenderItem() .getItemModelMesher() .register(item, 0, new ModelResourceLocation(Asolin.MODID + ":" + item. getUnlocalizedName(). substring(5), "inventory")); So you can see which function call is throwing an error, rather than just "somewhere in the entire line".

I think the issue here is that Minecraft's RenderItem instance is initialised after init and before post-init. So, to make it would you would need to move the item rendering registration to post init.