Control: severity -1 important Control: found -1 0.75-1 Could you be using Wayland by any chance, like with GNOME 3? For me, mate-panel crashes there regardless of applets used. Since the applet works fine for me, I hope you don't mind that I reduce the bug severity.
I suggest that you try invoking mate-panel from the command-line, attempt to add the applet again, and see if it gives any output that might be meaningful to be posted here.
signature.asc
Description: This is a digitally signed message part.