Harder Ores for 1.12.1 depends on Ore Flowers for 1.12.1 (does Harder Ores no longer have Ore Flowers functionality, or is this a doubling of the functionality?) and Ore Flowers 1.12.1 depends on COG 1.12.1 which does not exist (COG is only at 1.11). So because of a secondary dependency, Harder Ores is unusable (won't load) as is Ore Flowers, which one presumably shouldn't need in any case if using Harder Ores.
Harder Ores for 1.12.1 depends on Ore Flowers for 1.12.1 (does Harder Ores no longer have Ore Flowers functionality, or is this a doubling of the functionality?) and Ore Flowers 1.12.1 depends on COG 1.12.1 which does not exist (COG is only at 1.11). So because of a secondary dependency, Harder Ores is unusable (won't load) as is Ore Flowers, which one presumably shouldn't need in any case if using Harder Ores.