I saw this problem too
I came across various posts about removing and reinstalling network-manager and network-manager-gnome but that wasn't enough Then I tried manually editing the wifi AP settings to put in the password again and after that it is connecting to the AP. The desktop is GNOME Flashback too. I actually updated two identical laptops from wheezy to jessie on the same day and only one of them had this issue. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

