Just tried 2 times to mix in a crucible steel + nickel + black bronze and im getting unknown mix.

tried 8 steel 4 nickel 4 black bronze and bugged

tried 10 steel 4 nickel 4 black bronze and bugged too.

according to tfc documentation the % are inside the values for the mix

Nickel 15-25%
Black Bronze 15-25%
Steel 50-70%
6 steel 2 black bronze 2 nickel is a working ratio

added 2 steel to the mix to make 12 steel 4 nickel and 4 black bronze and not working mate