I have a problem with my wifi in Ubuntu (15.04). Recently, i have changed my wifi routers. Due to differents devices that was already configured, I have configured the new router with the same SSID and password, and this have worked for other devices but not for my Notebook with Ubuntu (in windows 7 in the same notebook it works!). Intriguinly, If I change the SSID of my router network,  it works in Ubuntu, but i don't want to change my SSID, because i have a lot of devices with this ssid/password stored.Why i can connect to my network except when the ssid is the same of my old network?Please, How can i fix my problem? Does someone know?
I can't connect to new router with same ssid that the older router
ubuntu;wifi
Every connection has a configuration file stored in /etc/NetworkManager/system-connections directory. Sometimes those files get corrupt and you cannot reconnect to the same network even though seemingly the file has all the info - password,essid,etc. So removing the specific file and reconnecting again, should help your case. For instance, sudo rm /etc/NetworkManager/system-connections/My Network Name