Comment 62 for bug 1434986

After upgrading 16.04 from 14.04 i face the same problem.

Then i got my solution. U can try this. By this network and wifi will be normal.

1 ==> open your terminal and type

      sudo nano /etc/NetworkManager/NetworkManager.conf

2 ==> change managed=false to managed=true and save the file

3 ==> again in terminal type

      sudo service network-manager restart

hope it helps.