I’ve been trying off and on to get this sorted for what feels like months now. Nothing’s changed the error message, no matter what I try, and i’m just completely lost at this point
I am on Kubuntu 25.04. Whenever I try to upgrade to 25.10, using do-release-upgrade, I get the following error
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 a
s 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.
i would appreciate any and all help on this. I’m just completely out of ideas at this point.
Probably better to check with the Kubuntu or Ubuntu community, they will know better how their distribution’s tools work
25.04 is past its end-of-life, approximately 9 months after its release. 25.10 is end-of-life soon.
The upgrade can be done with some editing of files, see EOLUpgrades - Community Help Wiki
If you have trouble, we’re very friendly at kubuntuforums.net.
A fresh install of 26.04 would be much faster than 25.04 → 25.10 → 26.04, but you’d have to reinstall stuff and restore your files.