Mystery Warnings

[Josephus]

I am getting a message at bottom of updates screen (see attached photo). What does it mean? How do I fix the problem and get rid of the messages? Thank you for all responses.

[claydoh]

No mystery. Well not too terribly much of one.

The error is from adding a PPA that does not provide any packages for Jammy (Ubuntu 22.04), so you will want to remove the old,outdated repo.

You can use the Software Sources tool found in Discover's settings to remove it, or, if you used the command line to add it as suggested by an outdated webpage, use the ppa-purge command to remove it, using the same syntax as the instructions did:

sudo ppa-purge ppa:alexlarsson/flatpak

If this had been a PPA that provided packages built for your *buntu release, this command would also downgrade any packages from there back to the stock, official ones. Simply deleting the repo information won't do anything like that at all.

[Josephus]

Thank you claydoh, but... "PPA-purge command not found", and I cannot find "software sources" in neither Discover or SystemTools:

<Some Time Later> After I wrote the statement above, my screen froze, then after rebooting, Firefox wouldn't work...Then tried to remove Firefox from Discover, no go.
At this point I was done...I kissed Kubuntu goodbye...and reinstalled my ol' Mate...sometimes old friends are the best.

This is my last time here (for now anyway). I appreciate all your past responses and best of luck to all!

[Schwarzer Kater]

You won't get rid of *Ubuntu-related problems by changing from Kubuntu to Ubuntu MATE - you just replace KDE Plasma and its core programs with MATE and its core programs, everything else will remain the same.
Having a wrong/unsupported PPA will have the exact same effect in Ubuntu MATE as it has in Kubuntu, for example…

In Kubuntu one could also start Software Sources in the Konsole terminal emulator with sudo software-properties-kde if one cannot find it in Discover's settings.

[claydoh]

Thank you claydoh, but... "PPA-purge command not found", and I cannot find "software sources" in neither Discover or SystemTools:

The error message likely would also have mentioned how to install it:

sudo apt install ppa-purge

But since you didn't have any software installed from that PPA, simply removing it via the GUI would have cleared the error, and not damaged anything.

And yes, you will have the EXACT same issue adding that same PPA to Ubuntu Mate (or any Ubuntu Flavour), unless you install an old version (20.04 Focal)
The fix would also be the exactly same: either removal via the Software Sources tool (wherever this is located in Mate), or ppa-purge.

[Josephus]

Mate is working perfectly, just as it always has. All the problems I had with Kubuntu are gone. Sorry to disappoint, but for me. Mate just works better (faster too). Thanks to all who tried to help. I won't see your responses, as this is definitely the last time I'll be here.

[claydoh]

So I get the last word??

This particular problem has absolutely zeeeroo connection to KDE Plasma or Discover whatsoever
As all the *buntus are quite literally the same exact distro, the cause and fixes are 100% identical.

Heck, both would be the same for Linux Mint and its brethren, as well.