Comment 24 for bug 1681513

I installed the future ubuntu 17.10 and found the same problem. Searching I found the following solution:

1) To stabilize the device:

$ Sudo apt install dnsmasq-base
$ Sudo service network-manager restart

2) To correct authentication error:

$ Sudo nano /etc/NetworkManager/NetworkManager.conf

Add in the end:
[Device]
Wifi.scan-rand-mac-address = no

$ Sudo service network-manager restart

After this procedure, it worked perfectly.
I consider the solution provisional and I hope they will correct it soon.

Source:
http://ubuntuforum-br.org/index.php/topic,121686.0.html