Upgrade 20.04 to 20.10 fails, missing updates

When trying to upgrade 20.04 to 20.10 using update-manager button Upgrade, I get a message that I must first install all updates. I did sudo apt update + upgrade and I installed all updates suggested by update manager. Now I get no message in the terminal, but nothing happens when I click the button Upgrade or use the command sudo apt -y update && apt -y dist-upgrade. Fyi: I have a triple boot system with Windows 10/Ubuntu LTS 20.04.1 and Ubuntu development version (currently 20.04.1) on tree different partitions (2 hard disks).

Solution 1:

You're on an LTS (long time support) version. There is some safety built in the system that you don't inadvertently upgrade to a non-LTS version.

To overrule this, just for this upgrade, do:

sudo nano /etc/update-manager/release-upgrades

and change Prompt=lts to Prompt=normal.

Then do sudo do-release-upgrade and your upgrade should proceed normally.