If the Quest counter is showing that new quests are available but there is no option to complete the Quests, this is because a new Class Event will be released, or you need to complete quests in another Kingdom.
Before a Class Event begins each week on Thursday, 7 AM GMT, the Gems of War team sends some files to the game to prepare the game for the new Class Event. These short Quests can be performed to unlock the Class used in the Class Event.
Once the Class Event begins, this message will disappear and you can complete those Quests from that Kingdom.
There are no quests available in Khaziel
This message may also appear for quests in Khaziel if you have not completed the other quests in Adana. If you cannot complete the final quests in Khaziel, try completing the first quest in Adana.
If you still have an issue, please contact Support.