Common ProblemsCan't start The Blood Gate after completing the Throne of Zuldazar achievement.
If the quest isn't available, it's possible you have not met the requirements. More information about quest eligibility can be found on Wowhead.
If you are unsure that the quest has already been completed, you can quickly check by typing the following command into the chat box in game: /script print(IsQuestFlaggedCompleted(47199)).
After typing in the script and hitting enter, if the number 1 is shown, it indicates the quest has been completed or if "nil" is shown, the quest has not been completed.
The quest The Blood Gate is a breadcrumb quest that leads you on to a larger quest chain. If you have completed the quest chain already, you will not be offered this quest. You will want to look for any of the follow ups. To check if you have completed the quest chain, run the following command: /script print(IsQuestFlaggedCompleted(47200)).