I have Kubuntu 24.04 lts. I tried following these two tutorials to upgrade to 26.04 lts:
https://computingforgeeks.com/upgrad…4-04-to-26-04/
https://www.fosslinux.com/155927/how…2026-guide.htm
and both times when I get to the step to run do-release-upgrade I get this:
$ sudo do-release-upgrade -c
Checking for a new Ubuntu release
There is no development version of an LTS available.
To upgrade to the latest non-LTS development release
set Prompt=normal in /etc/update-manager/release-upgrades.
I’ve read that the 26.04 release came out months ago, so I’m not sure why it can’t find it. My /etc/update-manager/release-upgrades is set to Prompt=lts
Why can’t it find the lts release? Thank you.
The message is very clear.
Kubuntu don’t marked any more release as LTS (for now).
You need to do other process (I don’t know wich, I don’t use Ubuntu or derivates) to update to a non-LTS version, as 26.04.
Regards
when 26.04 is ready, you will get a notification in your system tray (orange up arrow) to upgrade.
i’m currently on 24.04 and have not been offered the upgrade yet.
i would avoid those guides and just wait for the upgrade to show up.
if you must have 26.04 now, then you can reinstall the OS and get it that way.
Kubuntu upgrades are not related to KDE at all here for sure. You might find better guidance on a Kubuntu/Ubuntu specific resource 
But putting my Kubuntu hat on, it is true that Ubuntu does hold off on officially enabling LTS-LTS upgrades until somewhere around the time of the first updated ISO image “point” release (26.04.1) scheduled for August 4.
I’d say wait as it is close enough, but if you are eager to jump the gun, either switching the upgrade setting to “Normal release” or using the -d option should work. I have upgraded using both. If you did try this, and it did not work, then you do need to find what is blocking things. Not being fully updated, having some of those updates still being ‘phased’ for you at this specific moment, and even PPA conflicts maybe. These sorts of things are distro-specific, so you will get better assistance there.
i have mine set to “normal releases” and there is nothing yet because 26.10 has not been released.
waiting until the kubuntu team have got their plasma 6 upgrade ducks in a row is why i’m using kubuntu instead of struggling with a more cutting edge distro.
Using “normal” is a bit of a misnomer; it basically takes you out of the LTS-LTS loop, so it is no different than if you were running 25.10, where 26.04 IS a normal release.
As mentioned, I have upgraded one 24.04 PC using the “-d” method, as I always do for as long as there have been LTS releases, as well as doing the settings edit to get the GUI upgrader on another PC this past week, after the upgrade to the 7.0 kernel. I generally test upgrades before they are official, and the kernel bump that comes just before has been a good spot for this.
ah, i needed to reboot after changing it to “normal”
not going to do it just yet tho, i should be in a good place to handle any (more) weirdness next month.
You will be able to upgrade when 26.04.1 is released. That’s what’s usual. If you run a non-lts release, for example 25.10 then you will be prompted to upgrade to 26. 04 as soon as it’s released, but for lts-releases you have to wait for the xx.04.1 release.
that makes sense.
switching back to LTS releases and after a reboot the update prompt is gone again.
i can wait for the first point release.
