Using latest "classic-3" from Curse (manually installed).
Fully cleaned WTF folder and only addon enabled.
Doesn't change anything, just shows original nameplates.

Settings does show under Interface - Addons and /knp also open them

@Project-Version@ 2.4+debug
enUS DRUID
{profile=default}
{}
HealthBar, CombatUpdate, NameText, [LevelText], RaidIcon, [ClassPowers], [CastBar], Highlight, PowerBar, [AbsorbBar], [Threat], Auras, Classification, Execute, Fading, GuildText, PlayerAnchor, [TankMode], BossMods, [CombatToggle], BarAnimation, ArenaID, Target