Yep, same on Fedora. I had to edit /usr/share/applications/org.kde.kstars.desktop to get it working again, I changed "Exec=kstars -caption %c %i" to "Exec=kstars" as the problem seems to be the removed command line option.
Odd I don't know of any "caption" options even before, maybe it was some sort of standard option. At any rate, I did update the org.kde.kstars.desktop file so next update all should be fine.