On openSUSE 42.1 with latest KDE packages I just discovered the "Share" tab on a folder's properties dialog. And a bug :) ... It says "Samba is not installed on your system" (but samba is installed). When I click "Install Samba..." after giving root pw there is a loading animation which disappears after 10 seconds. Then one can select to share something. When I open the Share tab again, it's the same as before (samba not installed).
I forgot to mention: the samba package is installed and there is no message on the console.
Is this reproducible with more recent software? Last time I saw this, it was a legit error message, and successfully installed Samba when I clicked the install button.
See https://bugzilla.opensuse.org/show_bug.cgi?id=1013345#c4 . The code looked for smbd only in the user's path, but openSUSE installs it to /usr/sbin/ which is normally not in a (non-root) user's PATH so it wasn't found even if installed. Should be fixed since KDE Applications 16.04.2: https://cgit.kde.org/kdenetwork-filesharing.git/commit/?h=Applications/16.04&id=fb48a2e997eb76ff2eeff1e69c2db35478c2f0c0
I tried again on an recent openSUSE Tumbleweed system with this result: https://bugs.kde.org/show_bug.cgi?id=394273, original bug is fixed, but there are some details left.