I am upgrading from 18.04 to 20.04. I have updated 18.04. When I run:
$ sudo apt list --upgradable -a Listing... Done xscreensaver-data-extra/bionic 5.36-1ubuntu1 amd64 [upgradable from: 5.34-2ubuntu1] xscreensaver-data-extra/now 5.34-2ubuntu1 amd64 [installed,upgradable to: 5.36-1ubuntu1]
If I then run sudo update-manager I get a window that says:The software on this computer is up to date. However, Ubuntu 20.04 is now available(you have 18.04). When I click the Upgrade window I get: Please install all available updates for your release before upgrading. What do I need to do to complete the upgrade process?