It is better to update the current installation with latest packages first:
$ sudo apt-get update
Install update manager core if not:
sudo apt-get install update-manager-core
Start the command line upgrade tool
$ sudo do-release-upgrade
It is better to update the current installation with latest packages first:
$ sudo apt-get update
Install update manager core if not:
sudo apt-get install update-manager-core
Start the command line upgrade tool
$ sudo do-release-upgrade