KDE Kate no longer works with kio-slaves

After I upgraded from OpenBSD amd64 6.3 to 6.4 my KDE Kate program is no
longer able to open remote files (that is, to use kio-slaves).


When I try to open a remote (sftp:) file it says:

kf5.kio.core: couldn't create slave: "klauncher said: Unknown protocol
'sftp'.\n"


I was able to open an "http:" file supplying it via command line, but
then it says:

Non-native QFileDialog supports only local files


All other KDE programs (Dolphin, Okular, Gwenview, etc.) are still able
to correctly open "sftp:" urls, so the kio-slaves are correctly
installed and working.

I'd like to know if there is something bad in my system (maybe some
missing package, or a conflict with older versions?) or it is a (very
very important) limitation of the new Kate version.

Thanks.