used radiant echo on alt at worldsoul memory and then when try to use it on main it wouldnt allow me. said already completed that quest.
I have a Echo Radiant myself and it says to go to Dornogal but doesn’t show where.
I used my Radiant Echo (earned from using my coffer key in a Delve) on the Worldsoul in Hallowfall a few minutes ago and something confusing happened.
A big unattackable mob named ‘Dark Prophet Grshol’ appeared then despawned outside the Worldsoul sphere’s pond, then a big mob named ‘Bor’zal the Lurking’ spawned in the same spot as the previously unattackable one and I killed it, however when I went to loot it I was told ‘not eligible to loot’ it and received nothing from it.
A moment later a third mob named ‘Aqu’yinra’ popped up with a 1 minute timer to kill it and I killed it within time (no loot on that one at all), then a final rare mob popped up and I ran over and hit it… then the event abruptly ended.
I received or 18 ‘Coffer Key shards’, 36 Valorstones and an achievement for ‘The First Echo’.
Is this working as intended? It seems that this event was supposed to offer a nice reward and a story, however I have no idea what I just saw. 
It’s confusing, you don’t actually go TO dornogal, you need to leave FROM dornogal via the exit tunnel, then you will see on your map to go to from The Ringing Deeps to Hallowfall – you actually release the echo there (note that there is some type of rotation for which zone you release it in that changes weekly) – hope that helps.
I also have this issue, replicated using only a single character.
In my case I did a bountiful delve, got the first Radiant Echo (that starts a quest) and did the Worldsoul Memory with it. I did not realize that I could click on the quest in my quest tracker to complete it.
Then I went to another bountiful delve and got a second Unique Radiant Echo that starts a quest and sometime later noticed the completed quest in my quest tracker and completed it.
Now, when I go to a worldsoul memory (which doesn’t appear on my map) it says I don’t have a radiant echo in my inventory and when I attempt to use it from my bags it says I already completed that quest.
Blizzard either needs to make the quest version usable at all world soul memories or at least give us an option to exchange the quest version for the normal version (probably unlocked by the completion of the quest).
i guess when i got on my mount to go up on the mountain with a boss up top it kicked me out of the world soul with no rewards i don’t know how blizzards expects us to get to a boss on top of a mountain without mounting
Same issue here. I have the radiant echo in my inventory but the worldsoul memory is no where to be found.