-15000 error with Apple TV

Question

I'm suddenly getting this error trying to stream music to my Apple TV.
"An error occurred while connecting to the remote speaker "X". An unknown error occurred (-15000)."
I have iTunes 9.1.1, and an Airport Extreme with firmware 7.4.2.

Answer 1

try if any of the suggestions here help:
Some users that take advantage of the ability for iTunes to stream to external speakers wirelessly via AirTunes are finding that after upgrading to iTunes 9 their AirTunes capabilities no longer work properly. A growing thread in the Apple Support Discussions has users communicating their experiences with the issue.
The issue begins when users with previous AirTunes setups upgrade their iTunes application to the current version, 9. (Now 9.0.1.) ASD user "Vengance" reports:
It's [AirTunes] connected once or twice, randomly. Most of the time it says "An error occurred while connecting to the remote speaker "myairport'sname". An unkown error occurred (-15000)."
ASD user "westworthy" reports their experience:
I'm having the same issue. I try to stream to airtunes. I get about 2 seconds of audio then the audio stops, but the song is still playing. If I switch to the computer speakers you can hear the audio again.
There are many variables to examine when considering troubleshooting AirTunes. Of course you will want to be sure you have the latest firmware on all your AirPort Express units and be sure to have a stable backup of all your important data when attempting any troubleshooting steps.
Many users on this forum report that using earlier versions of iTunes on other computers on their network report no issues connecting and streaming to external speakers via AirTunes, so one option is to _*downgrade your existing version of iTunes 9 to iTunes 8.*_
Other suggestions for fixes include disabling the iPv6 setting in your AirPort configuration. ASD user "Joe-ri" suggests:
So people; when you have problems with iTunes not connecting to your AirTunes maybe you can try the following:
1) Open System Preferences
2) Open Network pane
3) Select Airport in the left list
4) Click the Advanced button
5) Go to the TCP/IP tab
6) Set the "Configure IPv6" field to Off.
7) Click "OK"
8) Click "Apply"
9) Let iTunes connect to your AirTunes speakers
Some users experienced improved performance after navigating to System Preferences > Security > Firewall and toggling it on, then off again, and rebooting their machine.
Users should also reset their network devices. Power-cycle your modem, router, and any AirPort Express units you have connected. Once everything has rebooted, check your AirTunes connections.
JGG