Apple recently added a setting to the Apple TV that allows for only user-verified devices to connect to the Apple TV. Trying to connect with AirParrot when this setting is turned on will result in this message being displayed: This AirPlay connection requires iOS 7.1 or later on iPhone or iPad, or OS X 10.9 or later with the latest iTunes on a Mac.
To disable the setting, go to Settings > AirPlay > Security > Require Device Verification and turn it off. This setting was introduced in Apple TV software version 6.1. More on device verification can be found at the Apple support portal.