Spawner Mob level help

This might just be me so i'm asking under support not bug report.

• • This is the level of the mob that should spawn from this spawner. Mob must have level configuration for this to work. Can only be a single level.
  • /mm s set Ruins_Skeleton1 moblevel 1-5 (Sets the spawner to spawn mobs between level 1 and 5)

Yea /mm s set Ruins_Skeleton1 moblevel 1-5 causes attribute invalid in versions 2.4.5 and 4.1 (both versions)

So all spawners can only spawn a mob of a...

Spawner Mob level help