Airplay mirroring not working

[rrschingler]

When I turn airplay on I get a black screen on my TV it has audio. For some reason mirroring will not turn on. Airplay drop menu shows Apple TV. Airplay and Apple Tv are both on the correct network. When I use safari I can play YouTube videos. I am using Imac OS X El Capitan. All Systems are up to date . I also ran disk utility its says everything is fine. Is there something else I should be doing

 

[silvetti]

I'm also having the same issue, no clue what happened...

 

[MotoGeekTX]

When I choose the Apple TV from the dropdown, the TV's screen goes blank. It's doing something, but that something isn't showing my desktop on the TV.

• Late 2012 iMac running OSX 10.11.4; it isn't too old
• iMac and Apple TV are on the same network (hard-wired, abandoned trying with wifi); it ain't the network
• All security is open on the Apple TV; it ain't the device's security settings
• Firewall on my iMac is turned off; it ain't the firewall on my computer
• I've verified there are no updates on my iMac or AppleTV; it ain't a bug fixed by software updates
• I do not have any AirParrot files on my iMac; there's no software interfering
• I've tried connecting to another Apple TV in the office setup the same way, but got the same results; it ain't the Apple TV device

Anyone have any idea what else may be causing the Apple TV to not mirror my desktop?

 

[afd]

i'm having the same issue. 2011 iMac, appleTV - 4 airplay mirroring not working, goes to blank screen. Airplaying video worksWorks fine with iOS devices but not mac. will try Apple TV 3 tomorrow. Has worked fine in past. Everything up to date, have restarted Mac, router and Apple TV, never installed Air Parrot. Seem to remember extended desktop was an option, not available now.
[doublepost=1471044826][/doublepost]Just tried turning off firewall from System Preferences. No joy.

 

[afd]

tried my apple TV 3 this morning with the same result.
[doublepost=1471083121][/doublepost]I had Duet display installed. I tried turning it off, but made no difference, uninstalled it and everything works again. Apart from Duet display ....