Yes ,had that problem last week too.   

As he evades all our melee-attacks and we have no spells, you need to click auto-attack and then use one of the new learned spells on him. Better have a spell haste buff on you though (bear shammy f.ex.) as you can't counter his first spell due to the refresh timer from attacking him.

But you won't die from that one spell-hit. 

Yes, Fujitsu, I talked to him, said that I'm ready and am supposed to attack him. Only that I can't. When I attack him, everything I get is misses, and after a few misses my autoattack is switched off automatically and I leave combat. I can't even use the newly learned spells since I am not in combat. Tried to use Whirling Storm after a missed autohit to force myself into combat, but it still says I'm not in combat.

Hag, thanks, I'll try that.

I've found a way around it:

- go to Khal into the caster trainer place (east side, northernmost room)
- get the quest from the charmcaster
- become a charmcaster yourself
- get an elemental charm from any charm crafter (crafting level 37 required)
- use theat charm on the umbral agent to engage him
- go on as the encounter is intended

Voilá!