[11:34:25] [Server thread/INFO]: Applying holder lookups
[11:34:25] [Server thread/WARN]: Unable to lookup CompactMachines:interfaceblock for public static org.dave.CompactMachines.block.BlockCM org.dave.CompactMachines.init.ModBlocks.interfaceblock. Is there something wrong with the registry?
[11:34:25] [Server thread/INFO]: Holder lookups applied

Server: Cauldron 1.7.10. "cauldron-1.7.10-1.1240.06.213-server.jar"

Sadly i cannot fix this because -foolish me- named the block id "interface" and I cannot use that as a variable name instead of interfaceblock, because it's a reserved keyword.
Nothing I can do about this, but also nothing you would have to worry about.

I can fix this easily at at point when worlds break anyway. Until then I will have to refer people to this Issue ;)