Migration assistant - automatic locations

In Snow Leopard when using Migration Assistant to import old user accounts/settings on or saved from another (older Leopard) computer to a new one or laptop etc., you may run into an issue where it imports modified or incompatible "Automatic" network "Locations" configuration settings from the older, other or incompatible computer, This could easily include importing wrong or incompatible "Locations" network information about the Airport card (and several other network proxy configurations) on the other (older or different) Mac.

The symptom of this is that the Airport will be permanently shut off and cannot be turned back on, by any Admin user.

As pointed out here elsewhere in the Leopard 10.5 answers, when airport would not turn on, it was suggested to delete it (use minus - facility) in the Network Preferences panel to remove the "Airport" service and hope the computer will rediscover the correct one and add it (as Airport anew or added as Airport 2) or allow the correct one to be added later. This will not occur nor cure the problem if it is in your "Automatic" Locations configuration1

The solution is to replace or delete the offending old/different imported "Automatic" Locations configurations. While logged in as any admin:

First in the Network "Location" dialog at the top of the pane, click the arrows and choose "edit locations".

It will then show a list of locations.(usually just the "automatic" one)

Click the + option and simply add a new one named "Adaptive". (or rename the existing "automatic" and make another new one)

It will "automatically" generate the correct system settings for you in this newly created/added "Location"

Make sure "Adaptive" (or whatever you named the new added one) is selected and click Done.

The Airport's functions will now return to normal.

If you use "About this Mac" System Profiler you can view the two different "Locations" under the Network-Locations contents index. Delete the broken imported one later.