Wireless Diagnostics popup impossible to close

Hi Tommy, had the same issue. The following worked for me:

Open the Activity Monitor utility

choose All Processes from the View menu

select the SystemUIServer process and click the Force Quit button on the toolbar.

Alternatively, you could open the Terminal, enter the command

killall SystemUIServer

And voila, its gone.

I'd go network In your preferences GUI

Then go into Advanced:

Click the offender;

REMOVE IT when

you click Ok and go back to previous directory/window

then Click apply

It may be working right away, or you might try refreshing the wifi cycle OR logging out and back in first if no immediate response.

You can ALSO try dragging the offending line to bottom, but if you don't need it, I'd cast stones at it until dead.

Wow, I have the same infuriating bug. I couldn't figure out what service was responsible for that filfthiness. Thanks to everyone who was able to provide the work around. Hopefully Apple resolves this one in the next point release.

thanks, jornvorn it worked!!!

Under the Apple in the Menu bar select Force Quit.

Select System Preferences

Click on Force Quit

I suspect unless you restart after the force quit, the problem will not be resolved.

In Activity Monitor, select All Processes not My Processes.

I'm surprised that System Preferences is not showing up in Force Quit window.

Try selecting the Finder and select Relaunch.