Latest ICC update today made it impossible to ride adaptive mounts in ground-only zones, such as Dalaran. Mounts like the X45 Heartbreaker and Horseman’s Reins can no longer be used as ground mounts. Please fix
This a deliberate result of how the no-fly zone in most of Dalaran works to prevent some mounts from being able to fly in from outside of Dalaran, land, and take off again. It’s only having this effect on flying mounts, so players can still move around Dalaran at ground riding speed (wherever riding is permitted in the city).
And all flying mounts may be used within the Krasus’ Landing part of Dalaran, as intended.