Trying to upgrade from 25.04 to any newer version, fails on authenticating update

[mtmarting0702]

Ubuntu Support Template

Ubuntu Version:
Example: 25.04

Desktop Environment (if applicable):
Example: KDE Plasma

Problem Description:
Running sudo do-release-upgrade results in an immediate error message and fails to upgrade

Relevant System Information:
Include any details that might help (e.g., hardware, drivers, or special configurations).

Screenshots or Error Messages.

Get:1 Upgrade tool signature [833 B]                                                                                           
Get:2 Upgrade tool [944 kB]                                                                                                    
Fetched 945 kB in 0s (0 B/s)                                                                                                   
/usr/lib/python3/dist-packages/DistUpgrade/DistUpgradeFetcherCore.py:180: Warning: W:Download is performed unsandboxed as root as file 'questing.tar.gz.gpg' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)
  result = fetcher.run()
authenticate 'questing.tar.gz' against 'questing.tar.gz.gpg' 
Authentication failed
Authenticating the upgrade failed. There may be a problem with the network or with the server. 

What I’ve Tried:
I’m gonna be honest, i’ve been trying to find a solution for months and i’m completely lost. Please help.

[celticwarrior]

Ubuntu 25.04 was not a LTS (Long Term Support) release. As such, its 9 months support ended last January. You missed the window for an online release upgrade (to 25.10).

https://askubuntu.com/questions/91815/how-to-install-software-or-upgrade-from-an-old-unsupported-release

[tea-for-one]

My advice would be:-

Backup your personal data
Download your preferred flavour of Ubuntu 26.04
Create a USB disk to run a “Try Ubuntu” session
Test your sound, graphics, wifi etc.
If satisfactory, install in UEFI mode with GPT
Restore your data

Two scoops are better than one

[qwedsaz]

Step 1: Check system time (most common cause)

timedatectl

sudo timedatectl set-ntp true

sudo apt install ntpdate -y

sudo ntpdate time.ubuntu.com

Step 2: Fix GPG keyring

sudo apt update

sudo apt install --reinstall ubuntu-keyring ca-certificates -y

sudo apt install gnupg -y

sudo apt-key update

Step 3: Clean and retry

sudo apt clean

sudo apt update --fix-missing

sudo do-release-upgrade

If none of the above works:

There’s a “wild path” that I’ve successfully used on PRoot containers to brute-force this exact upgrade. It’s extremely risky — ignores all GPG checks and forces the upgrade — but it works when everything else fails.

I’ve done it myself, so I know the steps.

Try the official fixes first. If you’re still stuck after that, reply here. I’ll walk you through the wild path.

But warning: it’s use-at-your-own-risk territory. You’ll need a full backup before we go there — if it breaks, you’re reinstalling.

[guiverc]

You’ve left it rather late; Ubuntu 25.10 is only days away from EOL when the release-upgrade process will be gone anyway. I’d not expect you’d need to use the unsupported upgrade instructions in the docs (EOLUpgrades - Community Help Wiki) but they maybe required because of your tardiness!

What I see is

• Your paste does not provide command, thus your command maybe in error (eg. no sudo was used to elevate privileges); you do mention sudo earlier; but not in pasted detail where it matters
• I see network issues; Canonical/Ubuntu infrastructure has had some issues of late & thus ‘problem with the network’ may only be a temporary issue which will work better at other times
• for sure I’d check system time as @qwedsaz already mentioned
• I note a python3 error!!; so I’d be checking you’ve not modified your system python in anyway; as that is a sure way to have problems like you describe… return your system python3 back to defaults if you have
• given Ubuntu 25.10 has only days remaining, I’d likely want to skip direct to 26.04, which if it was my own system, particularly if I was in a hurry, I’d achieve via non-destructive re-install, which still works with calamares used by Kubuntu. I talk about it in my answer here I was asked to write; sure it’s an old question (it fitted the answer I was going to write) but I actually used it to upgrade a Lubuntu 25.04 system to 26.04 here as I already had a 25.10 install for support purposes on that box. It handles Ubuntu repository (esp. deb) packages well; third party packages are different depending on how they’re packaged (decisions made by 3rd party packager can mean ‘nuke & pave’ or destructive re-installs are easiest as that’s what they’ve assumed), but it is an option I’d consider

You’ve made it harder on yourself leaving it this late though; knowledge of 25.04 is somewhat ‘stale’ now (esp. that upgrade path).

I can no longer look up details on what is correct for python or python3 for a plucky (25.04) release as that detail has been purged; so you’re really limited to those who still have a fully-upgraded system available they can use; but python is where I’d start checking personally.

[Dennis_N]

Maybe a bad package download? Try using a different repository mirror. I used the main U.S. repository.

I have an Ubuntu 25.04 vm, ran ‘sudo do-release-upgrade’. I got all the same terminal output, except that authentication mentioned did not fail and abort the process.

The process continued to calculate the upgrade, and I stopped at the ok to download the packages point.

encouraging output:

“10 packages are going to be removed. 106 new packages are going to be installed. 1242 packages are going to be upgraded. You have to download a total of 1,941 M. This download will take
about 6 minutes with a 40Mbit connection and about 51 minutes with a 5Mbit connection.”

Looks like it would go. At that point, I declined to continue, as I didn’t want to upgrade to 25.10

[masonreed11t123454]

Ubuntu 25.04 is EOL now, so the normal upgrade path won’t work. The easiest and safest fix is to back up your files and install a supported release ideally the latest LTS. Using old repositories can work, but it often causes package and dependency problems.