“An Ancient Hunt”–the Chronomancer in the Council Chambers had no dialogue option to speak to him. I cant complete the quest.
Welcome to the forum.
This is an old known issue with that quest that has not yet been resolved. It seems to be related to the intermediate step of “hearing the roar” of the dragon first. For some, it seems to work if they run around exploring the map (without approaching the dragon) until they get the “hear the roar” notice and then if they kill the dragon the quest completes properly.
You can try that to see if it works for you.
Note: Please be sure to verify the game files (via Steam) to make sure your install is ok - odd quest issues can sometimes happen if the install is messed up.