When I try and access national quest from the class hall, the following message appears. " president..

On Saturdays Battle for the launch center your state will get a new president. All the quest buildings are recalled and the new president needs to place them before you can quest. If your state loses the battle then you may not have any building for the next week.

If you do have your president and they have placed the buildings then it may be a minor glitch. Closing and restarting the app should correct this and let you send to the quests.

For more questions for Last Shelter: Survival check out the answers page where you can search or ask your own question.