Although the quest “Mysterious Greenery” appears on the world map, the NPC quest giver “Glimmercane” is missing currently on Live 9.2 for the quest chain that should be offered after completing Sopranian Understanding research for the Cypher of the First Ones system.
Edit: This issue seems to have been fixed tonight around 7pm eastern on US servers.
Is this quest a prerequisite to being able to create mounts with protoform synthesis?
I did my Sopranian understanding, this quest is unavailable, and I can not see any of the open world patterns for the mounts.
Unavailable for me as well. Made sure I was on late last week to start the research ASAP and apparently that was worthless
No, the questline to craft mounts is still able to be completed without Mysterious Greenery, even though they unlock from finishing the Sopranian Understanding research at the same time. The quest line you’re looking for is the other one that unlocked over in Pilgrim’s Grace, called “Finding Tahli.”
Just be aware, the quests along that chain have a few spots where it seems like you deadend, but you just have to wait a few more seconds for the quest givers to appear. There was one spot in particular that had a new step in Pilgrim’s Grace after I completed the “Judgement Call” quest. The new one picked up in Pigrim’s Grace will then be named “The Lost Component” and that will finish the last few steps to unlock the ability to craft mounts.
Same issue, quest marker on the map, no NPC. Wowhead article said the questgiver was also missing on PTR
I swear there’s something bugged with every step of the cypher research. Farming cyphers and doing the research ASAP is just testing for others 
Same issue
Was able to complete the main chain to unlock mount synthesis but Mysterious Greenery is still missing, as others have mentioned here. We lose out on being able to claim the final treasure for the zone achievement but not sure what else.
I am checking here again to confirm that the questgiver is still missing after the reset.
same issue
same for me
same issue here as well
No npc near quest marker.
same for me
Same here for me
Same here!
Same issue here on Feathermoon/Scarlet Crusade.
This is what i came to find. No quest giver for me on Durotan/Ysera
Same here, tried phasing, realm hoping and wm on/off. Nothing works
+1 same here