NetworkManager fails to connect wirelessly, with "Failed to add/activate connection...No session fou

I bring OpenSuSE 13.2 up-to-date almost every week. Wireless connection using NetworkManager has worked faultlessly until the upgrade I did today. Now, after rebooting, I get wireless connection, but after some minutes it then fails. When I attempt to reconnect by left clicking on the icon, I get the message:

Failed to add/activate connection...No session found for UID...

I am able to connect to the modem with a cable and then all works well.

I have tried restarting NetworkManager with

rcnetwork restart

but it makes no difference.

I have another computer able to communicate wirelessly through the same modem so I don’t believe it to be a modem fault. Has anyone else observed the problem and have a solution?

And which “upgrade” did you do today?
There were no updates today…

Now, after rebooting, I get wireless connection, but after some minutes it then fails. When I attempt to reconnect by left clicking on the icon, I get the message:

Failed to add/activate connection...No session found for UID...

Sounds similar to:
https://bugzilla.opensuse.org/show_bug.cgi?id=923225
and/or
http://bugzilla.opensuse.org/show_bug.cgi?id=923387

I have another computer able to communicate wirelessly through the same modem so I don’t believe it to be a modem fault. Has anyone else observed the problem and have a solution?

Everything works fine here.

You could try switching to “Wicked Service” instead of NetworkManager (YaST->Network Devices->Network Settings->Global Options), does it work then?
You’d have to setup the connection in YaST then, though. (select your wireless adapter and click on “Edit”)