I am already in airplay mirroring so why does the following message keep coming up. "video streming in SQ is not supported for airplay|(non mirroring). Please switch to auto streaming mode or switch to airplay mirroring"

Please give your ATV version and software version.

When you say "SQ" do you mean "SD"?

What platform are you trying to mirror from, iPad, iPhone, MAC?

What app/program are you running which is giving this message?

Have you updated your app/program to the latest version?

Have you updated ATV to the latest version?

Have you checked the website of the app provider?

Are you sure mirroring is turned on? On iPad/iPhone it's a separate switch on the AirPlay popup menu. On a Mac it's a little different, see Use AirPlay to display video from your Mac on an HDTV - Apple Support

This is a couple months old, but will offer my answer in case someone has the same problem as I just did.

I Received this same error while trying to stream my Slingbox video.

what I noticed was that the error popped when I was streaming, not simply mirroring, which suggested the error was with the video source ( Slingbox).

in the Slingbox app under SETTINGS is a VIDEO QUALITY and there are 2 sets of options -- CELLULAR (top) and WIFI (bottom). My wifi (what I was using) was set to SQ quality. Changing to AUTO fixed and the error went away.

good luck.