'Your network settings have been changed by another app' - THE SOLUTION

The “problem” died an early death after dumping a few net prefs.
Eric

That was suscinct at to the point but of moot in the value department.
Eric

if i cant access airport via preferences/network, how can i access the information i need in order to refill the various settings after deleting the configuration files?

To stop the pop-up, Go to System Preferences: Security. Check the box next to "Require password to unlock each secure system preference." Then lock Security.

I find it interesting that this bug -- which is a show-stopper for the average user afflicted -- has been well documented by THOUSANDS of posts in this forum across many threads for 18 months now... and it is still not fixed, or even acknowledged by Apple.

Today, I have a client visiting Mexico, and she's in a panic because her computer is her lifeline and she can't get on-line anywhere, because of this bug. Now we have to play phone tag across international borders so I can walk her through a kludge fix, one click at a time...

...Thanx, Apple. 'preciate that.

yep...the solution is pretty easy, if you know what to do.

you'd think that after installing one of those software update things you get to download that supposedly address security concerns, it wouldn't require a user to find out somehow or other that it's a password issue causing new mail problems following the "fix". that happens to be related to security, one might imagine. but did that get modified by one of those software updates? was it there in preferences before, or was it inserted into the os to "fix" something? who can remember what was in there before? was it?

it's been a recurring bug, yes, for some time now, as many of us have learned, which is why i use mozilla thunderbird except for emailing photos out of iphoto. but it definitely bugs me when i can't get into network preferences now and then to deal with network issues.

Genius Jona, you're my hero, thanks, Cameron

I have just tried the solution offered, i.e., gone to Library/Preferences/System Configurations and deleted the four specified files, com.apple.airport preferences.plist, etc. I then restarted my machine, and was disconnected to the Internet. I did have to configure my settings. No problem with reconnecting (Airport). However, when I went to System Preferences, the problem was not solved! The drop down message is still there and I still have to force quit System Preferences. Any alternate suggestions for getting rid of this annoying drop down.

Am I the last person to experience this problem? A big thanks to everyone on this lengthy thread for all the advice. I eventually cobbled together the essential info needed to get rid of this message, though it took me an awful lot of reading.....

thanks again

To stop the pop-up, Go to System Preferences: Security. Check the box next to "Require password to unlock each secure system preference." Then lock Security.

I follow the instructions and I solved the problem, but delete these registry files has produced some disadvantages: I have lost some settings of amsn, for example the emoticons (except the default ones), that I can't use even if they still are in their folder in amsn preferences... some idea?

After installing Security Update 2009-001 and later, 2009-002, I have faithfully executed all of your suggestions (several times), only to be left with the requirement of manually entering my dial-up passwords, and allowing NetConfigTool and pppd permission (manually), before I can even connect. Is this another problem altogether, or is it still related to "your network settings have been changed by another application. I suspect my Keychain has been tampered with. Now that I try to permanently allow NetConfigTool and pppd permission within Keychain Access, I cannot, since I don't know my Keychain password, having never set a Keychain password. Please advise.

Thanks Jona & anyone else with ideas. I had a few problems with solutions but somehow it all worked OK and I'm back in business.
Mother Load

Thanks Jona.

This fix worked.

Brilliant.

Sorry , and heeeelp , it does not work for me , The Netcfg does not appear but there is no automatically online action when i start the browser .
Does someone knows a solution ??????