Hello,
here is my quick solution.
Realized, that all quests were running in the back.
You have to remember on which part you lost the quest-line and just
take the tasks (kill this, go there) and finish it.
You will see no messages on the screen, but if you succeed,
your quest-npc will show up again (also remember which one is yours atm)
and you are able to finish the quest, get reward and go on.
In case of T4 - Darkelves "the ebon flame" it works for me.
Find the mob to kill and went back to npc in Ch.18.
From this point going on til the end, in group.
Reward an epic shield ...very nice look.
Today I will try it in T4 Empire/Chaos, with "Annihilation".
I barely remember the task and know where the quest-npc is hanging out.
I am sure it will work.
I think it occurs while you disconnect in some way.
Joining a SC for example.
Or leave the Group, while running the quest-line.
Maybe too much quests in your ToK, just delete 10-12 from T1-T2 if you like.
Try to start such a quest-line and do it in one straight way.
Strange thing was, parts of the quest seems already finished,
without even doin anything.
I may say thanks to Mazadun, for making these videos,
where I was able to re-check the parts I have completed and which one was missing.
https://www.youtube.com/watch?v=u01y-a4fj9Y
https://www.youtube.com/watch?v=FmBsL3wSSSU
https://www.youtube.com/watch?v=1r42h9AKSxQ
Please try it out.
In this server-stage it is clear from the beginning,
that some quest may seem slightly bugged.
Or in other words...find your way to complete it.
I hope this helps.
Thx and see you on the fields of war/ror