When I select a UAV in Horizon’s Autopilot Control list I see a message saying it is unable to create the UAV (error 3072).

[Evan Schellenberg]

User Account Control (UAC) in Windows Vista, 7 and 8 prevents the Horizon UAVs from being created unless you run Horizonmp as the Administrator of the computer. The easiest way to do this is to right-click the Horizon shortcut icon on your desktop and choose properties. Then select the Compatibility tab and tick the setting for Run As Administrator. Click OK to save the setting.