This is an issue in YAMDA where there is have a custom Nether Biome to allow the ability to prevent the spawning of caves and other features: https://github.com/Sunekaer/YAMDA/blob/1.15.2/src/main/java/com/sunekaer/mods/yamda/netherdimension/YAMDANetherBiome.java

Because the Nether Dimensional Shard ore is only spawned in The Nether (Unlike the normal ore which appears to gen in all dimensions) it means it won't appear in the YAMDA Nether Mining Dimension: https://github.com/McJtyMods/RFToolsBase/blob/1.15/src/main/java/mcjty/rftoolsbase/worldgen/OreGenerator.java#L46

The easiest fix I can see would be to set the Nether Dimensional Shard ore to spawn where biome.getCategory() == Biome.Category.NETHER; or just have it spawn wherever there is netherrack (Like how the normal ore does for stone).

Is that possible?

Or do you have another suggestion on how we could get the Nether Dimensional Shard ore spawning in the custom dim/biome?

Thanks

What version?