Blackstar Quest Bug

I did a video to explain better the situation...
In the first time doing the quest i died to boss, and i couldn't respawn, after some trys i restarted the game and no changes. The game request me to choose 2 ways again and i did all quests of other way ( i mean 1000 mobs and got 3 weapon bosses again ). And when i reach the quest "[Blackstar Weapon] To the Altar of the Fallen God" i couldn't spawn the boss, looking im already doing the quest but nothing happens.

I know how this quest works and i already waited 3 days and nothing...

video link :

hellp pls !

 

This should be posted in bugs...not Problems...but you can always try to start a Conversation with @Kolka, our resident problem solver

 

Open your quest log [O], go to ongoing quests and look for a quest with the name beginning with [Battle] and forfeit that quest then try to summon the boss again.

 

I had similar issues with the quest on an alt. I selected the hard version and got all the way to the boss. But when he disappears and summons the instable shards, I desync'ed three times in a row. Always at the shard phase and by desync I mean lost connection to the server, still in the game world but no input from my client did anything. I had to alt-f4. I logged back dead and by the third time, the quest autocompleted as if I had killed the boss.
I've did the quest several time in the past without issues though.