Non-802.11n AirPort Expresses and Extremes are not compatible with AirPort Utility 6, so that's the reason why you receive that message. It doesn't mean that you can't connect to your AirPort anymore, but you won't be able to set it up.
To set up your AirPort, install AirPort Utility 5.6. As the normal installer doesn't work, follow the steps in this site > http://frank.is/mountain-lion-and-the-old-airport-utility/
I'll give 5.6 a try with your extractor method but was hoping to find a way to use the latest airport utility because Apple explicity lists it as being compatible in their downloads page http://support.apple.com/kb/HT1998
AirPort Utility 6.3 for OS X OS X v10.7.5 or later AirPort Express 802.11n (2nd Generation), AirPort Extreme 802.11n (1st Generation), AirPort Express 802.11n (1st Generation), AirPort Time Capsule 802.11n (1st Generation), AirPort Extreme 802.11n (2nd Generation), AirPort Time Capsule 802.11n (2nd Generation), AirPort Extreme 802.11n (3rd Generation), Time Capsule 802.11n (3rd Generation), AirPort Time Capsule 802.11n (4th Generation), AirPort Extreme 802.11n (4th Generation), AirPort Extreme 802.11n (5th Generation), AirPort Time Capsule 802.11ac, AirPort Extreme 802.11ac
(1st Generation), AirPort Express 802.11n (1st Generation), AirPort
Check the Model No on the side of your AirPort Express. A 1st Gen model is A1264.......which works fine with AirPort Utility 6.x versions.
Is this the model number that you see on your AirPort Express?
If you see A1084 or A1088, these are much older 802.11"b/g" versions. Apple started using the "generation" name with 802.11"n" products.
I did all of these steps, and then tried to open Old AirPort Utility, and it says "You can't use this version of the application 'Old AirPort Utility.app' with this version of OS X." (I'm on Mavericks / 10.9.) Sad face! Does this mean I have to shell out $200 for a new pair of Airport Express devices? Thanks Apple!
You can use another Mac running Leopard or Snow Leopard, or a PC to administer the older AirPors.
If you don't have one of these computers, maybe you could borrow one from a friend for a few minutes.
If this is not possible, then you will need to add new AirPort Express devices to work with Mavericks.
mende1, that link you posted that ultimately led to corey mahler was brillant.
it allowed me to use airport utility 5.6.1 while running mavericks to update my way old airport expresse's firmware and connect it to my network for use as a wireless extender. the whole process was a cake walk.
thanks a lot and, obviously, thanks corey.
Please tell me how you did this. I have one extreme model A1354 working well but want to extend with an old A1034. I am using Maverick on my laptop so version 6.3.2. My laptop sees the old airport but won't let me set it up.
I think you may have had a similar problem. Can you please walk me through the solution?