10/23/2015
The subclass quest step "Complete the Path" may say "Incomplete" even after obtaining a fully unlocked build.
In order to complete the quest step "Complete the Path" the same subclass must be equipped that was used in the previous quest step ("Create 25 Orbs of Light").
To resolve this issue, equip the subclass used in the previous quest step in any location, return to Orbit, then visit the Tower and speak with your Vanguard mentor.