Five Keys to Success quest is bugged at
Ready Your Companion part.
Steps I did:
1. I have chosen first option (Man-at-Arms) from a NPC (I think it was Engong) that gave me Ready Your Companion quest part
2. Then I bought green version of Man-at-Arms from AH
3. Then opened inventory and double clicked on the green version of Man-at-Arms
4. Then summoned Man-at-Arms
But the quest did not progress since I guess I was supposed to double click on the White version instead:
Thanks to the tips I found
here (btw it's 8 months old) I've managed to complete the quest.
I put the white Man-at-Arms on bank and then to shared bank and it didn't work, then I put it on AH and it worked for me (someone mentioned that destroying it works too).