Airport utility doesn't support my airport express

Question

I just noticed my Airport Express isn't showing up in the Airport Utility, i mean, it shows up but there's no light on, not green or orange, just no light at all. When i click on the icon in the Airport Utility, it says this version of Airport Utility (v.3.6.1) doesn't support this base station.  The Airport Express is quite old, i've had it for many years, not sure how long, probably first or second generation. It says it's model A1084, 2005.
The Airport Express has always worked fine with my previous computer, MacBook, currently OS 10.6.8, and with my new computer MBP OS 10.8.5. I used it with AirTunes to play music through external speakers on the old computer.  With the new OS, it was using Air Play. The old Airport Express worked fine.  I got the new computer in November.  I was using a very old Airport Extreme as the router.  In late December, i got a new Time Capsule.  Software update was run and after the Time Capsule was installed, the Airport Express still played music. The green light lit up in Airport Utility.  I played music through the external speakers as recently as a couple of weeks ago, both in iTunes and on You Tube.
I don't know why music is not playing through the external speakers now. The device shows up in Airport Utility but it appears dead and i get that message saying the the version of Airport Utility doesn't support the base station.  The green light is on, on the Airport Express. i have not updated the Airport Utility since late December when the Time Capsulre was installed. 
The only thing that has happened recently, though i don't know why it would make any difference, is that a few days ago for the first time, i did a backup of my hard drive to the Time Capsule, using Time Machine. I had not done this before since i got the Time Capsule, it was the first time. Other than that, i haven't installed any new software and haven't done anything differently that i know of, although a few days ago, i clicked OK on a box in You Tube and my You Tube account now no longer has any of my favorites or playlists. It's the same account as far as i can tell, i didn't log out, it was still logged in when this happened. While that is a disaster, it doesn't seem related to my external speakers not playing all of a sudden.
Is there anything i can try in order to fix this?  thanks

Answer 1

The Airport Express is quite old, i've had it for many years, not sure how long, probably first or second generation. It says it's model A1084, 2005.
This would be an 802.11g AirPort Express base station. There is only one generation of this version.
When i click on the icon in the Airport Utility, it says this version of Airport Utility (v.3.6.1) doesn't support this base station.
I'm not aware that Apple produced a v3.6.1. Did you mean v5.6.1 instead? If so this version is meant to administer these older 802.11g AirPorts on Macs running OS X Leopard or Snow Leopard. More precisely for versions 10.5.7 thru 10.6.8 ... so your MacBook should be able to run this version of the AirPort Utility.
I played music through the external speakers as recently as a couple of weeks ago, both in iTunes and on You Tube.
If you are streaming from YouTube, then you must be using a third-party solution like Rogue Amoeba's Airfoil. Is this correct?
The only thing that has happened recently, though i don't know why it would make any difference, is that a few days ago for the first time, i did a backup of my hard drive to the Time Capsule, using Time Machine.
You're right. That should have not made any difference as far as streaming goes.