Today I wasn’t able to select a queue while creating a build definition or queuing a build using the new build engine that comes with TFS 2015. The drop down was blank.
This problem may occur if you don’t have build queues for your Collection or if you don’t have permission to use the queues in your build definition.
Go to the administration site for your collection
Check if you have queues for Collection
If you do, select your queueà Role à Agent Queue Users à Double click on Agent Queue Users à add users or groups
Otherwise click the “New queue” link to create a new queue