Pixelmon Mod

So, I got a Gengar, and on the wiki, it says it can learn Shadow Ball, so I got a TM of Shadow Ball, and right-clicked, and the chat said, "Gengar can't learn Shadow Ball!!" even though the wiki says yes it can. What am I doing wrong?

The wiki isn't fully up to date with learn sets atm. All stats have been updated to their latest main game appearance, which in Gengar's case means Gen8. It learns Shadow Ball via level-up to lvl 48 or from TR33.