I need to upgrade ubuntu 16.04 to 20.04. When I use graphic interface, a pop-up windows tells me that all is updated and Ubuntu tells me that 18.04 must be installed first that it is normal.
But when I click nothing happens.
When I use the command line : sudo do-release-upgrade
I have the message :
Please install all available updates for your release before upgrading.
I don't understand. Anyone has an idea ?
Sorry for my bad english
Thanks you very much.
Yes, in fact, I had errors during sudo apt update. So I remove some deposits (skype and others). Now it's ok. I can upgrade 16.04 to 18.04.
use sudo apt update && sudo apt upgrade && sudo apt full-upgrade and then upgrade to 18.04 and then to 20.04
You need to ensure your xenial or 16.04 system is fully-upgraded before you can release-upgrade.
The error message is telling you that you haven't applied all 16.04 upgrades.
I'd suggest
sudo apt update
and read the messages, ensure there are no errors (or lines are missing), then
sudo apt full-upgrade
and providing all upgrades are applied (and no sources are missing from the apt update you ran earlier), you may need to reboot, then the do-release-upgrade should work.
