I am unable to enter Reinhold's Retreat for The Missing Guardian quest.
I have completed the prerequisites for The Missing Guardian (The Corrupted Stone, Warrior's Call, The Elemental Army, and The Shattered and the Lost) and had 4 people including myself to activate the switches to open Reinhold's Retreat. I am prompt to enter which says "Enter Reinhold's Retreat" in white, and once I prompt my enter command ("E") it greys out. I think it's a bug because have reactivated the quest countless times, logged off/on, and even completed Wrothgar in between.
What is preventing me from entering?