Running a Imac; OSX 10.9.2 and a ATV3. Whenever I try to run Airplay from my Imac; all I get is a black screen on my Tv which of course is connected to my ATV3. I have 2 ATV3 hooked up to 2 Tv's and I have the same problem with both. I have tried beamer from my Imac; and it gives me an error of failing to connect. I also have a MacBook Pro that I can use; and it connects perfectly to both ATV3; via Airplay and Beamer. I do run Plex on my Imac and it works perfectly with both ATV's. I just recently installed a script on my Imac for Plex; so that it would start automatically whenever the Imac is booted. Don't know; this may be the problem; however, I do not know how to remove the said script in order to determine this. The script is as follows: cd "/Applications/PlexConnect-master/support/OSX" sudo ./install.bash Any suggestions?