Can't upgrade Ubuntu 16.04 to newer release

I have a HP EliteBook 2540p. I want to upgrade my Ubuntu 16.04 to a newer release. I found that I need to upgrade to 18.04 before going to 20.04.

I tried the recommended procedure by updating the system and upgrading software and packages using this command:

sudo apt update && sudo apt upgrade
Hit:1 xenial InRelease
Hit:2 xenial InRelease
Hit:3 xenial InRelease
Hit:4 stable InRelease
Ign:5 stable InRelease
Hit:6 stable InRelease
Hit:7 xenial InRelease
Get:8 xenial-security InRelease [109 kB]
Hit:9 xenial InRelease
Hit:10 stable Release
Get:11 xenial-updates InRelease [109 kB]
Get:12 xenial InRelease [66.2 kB]
Hit:13 xenial InRelease
Hit:14 stable InRelease
Hit:15 xenial InRelease
Hit:16 xenial InRelease
Hit:17 xenial InRelease
Hit:18 xenial InRelease
Get:19 stable InRelease [4,502 B]
Hit:20 xenial InRelease
Hit:21 xenial InRelease
Hit:22 xenial-infra-security InRelease
Get:23 xenial-backports InRelease [107 kB]
Hit:24 xenial InRelease
Hit:25 xenial InRelease
Hit:26 xenial-infra-updates InRelease
Hit:27 xenial InRelease
Hit:29 xenial InRelease
Hit:30 any InRelease
Hit:31 any InRelease
Err:19 stable InRelease The following signatures were invalid: KEYEXPIRED 1624268195 KEYEXPIRED 1624268195 KEYEXPIRED 1624268195
Hit:32 jessie InRelease
Reading package lists... Done
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: GPG error: stable InRelease: The following signatures were invalid: KEYEXPIRED 1624268195 KEYEXPIRED 1624268195 KEYEXPIRED 1624268195
E: The repository ' stable InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome.list:3 and /etc/apt/sources.list.d/google.list:1

I think I can't get all the updates and upgrades that I need, and I don't know what is the problem.

After that I tried this command to check the available release:

$ sudo do-release-upgrade -c
Checking for a new Ubuntu release
New release '18.04.6 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

It looks like it's working, but when I try the command to upgrade, it doesn't work:

$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.

I don't know what the problem is.

1 Answer

In short, you waited too long to do this easily and effectively.

16.04 is already past standard support, which means that there are no longer updates unless you are on Extended Security Maintenance (ESM). You need to perform updates before you can upgrade to the next release, which you can't do without using ESM. Hence the problem.

You could sign up for ESM, perform your system maintenance, and theoretically should be able to upgrade to 18.04 without incident.

But since you want to be on 20.04, it doesn't really make any sense to release upgrade. You can't easily skip over releases when upgrading and there's always a potential for an upgrade to be unsuccessful, depending on your hardware and whatever is already installed on your system, especially if you have any software that didn't come from Ubuntu repos. Release upgrades also take a long time to complete.

It's probably better that you cleanly install 20.04 at this point. Remember that LTS releases come with 5 years of standard support and if you don't want to be in this predicament in the future, make sure you upgrade in a timely manner. You have three whole years to upgrade after a new LTS to the next LTS before it becomes unsupported.

You can also sign up for the ubuntu-announce mailing list to get emails about new releases and EOL announcements: