SUMMARY

Plasma Discover shows "Applications cannot be loaded, please check your internet connection" (translated from German language) on start page. Network is of course fully operational. I believe this issue is related to lack of support of the distribution I chose: Devuan.

As terminal output indicates this might be related to downstream projects PackageKit and AppStream:

I am willing to report issues for these downstream projects and reference them here. If you have a little advice on how to do that in a way that is most helpful, please share. Otherwise I try to look for their bug trackers myself and report in any way I see fit. But maybe you have some helpful tips.


STEPS TO REPRODUCE

1. Run Plasma Discover on Devuan Ceres.

OBSERVED RESULT

"Applications cannot be loaded, please check your internet connection" on start page.

In Konsole output:

[…]
PackageKitBackend: No distro component found for "org.devuan.devuan"
[…]
AppStreamIntegration: No distro component found for "org.devuan.devuan"


EXPECTED RESULT

Works on Devuan which is basically just a fork of Debian with another init system than Systemd.

Also for the error message: Gives a meaningful error message. This is certainly not about a non working internet connection.

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: Devuan Ceres which is based on Debian Unstable
KDE Plasma Version: 6.3.2
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2