Comment 3 for bug 1858011

I can confirm this by changing to Turkish language, logging out and back in, and then opening Discover.

This is somehow related to AppStream but I'm a bit unclear how.

Running in terminal produces:
adding empty sources model QStandardItemModel(0x555778d00810)
Could not open the AppStream metadata pool "Unable to add data: MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size"
no packages for "libgphoto2"
kdeinit5: preparing to launch '/usr/lib/x86_64-linux-gnu/libexec/kf5/klauncher'
kdeinit5: Launched KLauncher, pid = 2619, result = 0
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
kdeinit5: opened connection to :0
kdeinit5: Got EXEC_NEW '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/http.so' from launcher.
kdeinit5: preparing to launch '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/http.so'
qml: message: Please make sure that Appstream is properly set up on your system
kf5.kio.kio_http: Can't communicate with kded_kcookiejar!
took really long to fetch KNSBackend(0x555778d05950, name = "/usr/share/knsrcfiles/discover_ktexteditor_codesnippets_core.knsrc")

That AppStream error (MDB_BAD_VALSIZE) turns out to be an issue, again specifically for Turkish, for elementaryOS' app store:
https://github.com/elementary/triage/issues/6

Also perhaps related, I also get an error "Please check your connectivity" instead of the "Featured" content that seems related to AppStream:
https://bugs.kde.org/show_bug.cgi?id=409220

FWIW the "Featured" content comes from here:
https://autoconfig.kde.org/discover/featured-5.9.json
And for grins I checked on appstream.ubuntu.com for all the ones that normally show up (Inkscape and KDE SDK do not), all of them have a "Name" in "tr," so it shouldn't be a translation issue.