**This article relates to AirParrot 1. As of September 2016, support for AirParrot 1 has ended. We encourage you to upgrade to AirParrot 2 for the best compatibility with new devices.**
Close AirParrot, wait a few minutes, and then re-open it (The waiting part is important). Make sure you don't have any firewalls (software or hardware) and make sure iTunes can see your Apple TV as an Airplay devices.
If this doesn't solve the problem, your computer is unable to see your AppleTV. Be sure both devices are connected to the same network and have an IP address that's in the same subnet. Your network must also allow Bonjour and mDNS services.