There are a few reasons this message may be presented. It's generally caused by a port or name conflict with another service being broadcast on the network.

This issue can usually be resolved by opening the Reflector preferences and changing the AirPlay receiver's name. Be sure there are no special characters and that the name isn't abnormally long.

If this doesn't solve the problem, try opening Activity Monitor and closing any other AirPlay services (AirDisplay, AirFoil, AirServer, etc.). We've also noticed that certain software by AutoDesk can cause issues (SW_server). This includes Stone and Wire, AutoCAD and 3DSM.

To check for blocks on required AirPlay ports, you can run this command in terminal:

  • sudo lsof -P -i :7000 -i :47000 -i :7100 -i :49228 -i :50259 -i :62572 -i :54780
You'll be presented with a list of ports being blocked (if there are any). This should give you an indication of what application to close. If you notice either of the following two lines, you'll need to take special steps:

  • sw_server 399 root 17u IPv4 0xa27e7fa107bd0c23 0t0 TCP (LISTEN)
  • sw_server 399 root 18u IPv4 0xa27e7fa107bd04eb 0t0 TCP localhost:7000 (LISTEN)

These are services that are started and run constantly when AutoDesk software is installed.

To stop the service, open terminal and type:

  • sudo /usr/discreet/sw/sw_stop

If you need to start the service again, you can run this command:

  • sudo /usr/discreet/sw/sw_restart

More information about this AutoDesk service can be found here.