I ran into this after an update from 16.04. I had a custom panel as well but I found a way to show the notification panel again without resetting the dconf configuration. I had three indicator-application.desktop files (and I IIRC likewise as many probably competing running instances of it):
/usr/share/mate/autostart/indicator-application.desktop /etc/xdg/autostart/indicator-application.desktop /usr/share/indicator-application/upstart/xdg/autostart/indicator-application.desktop Only the last one seems to be the current one. I have removed (renamed) the first two. I have not tested if that alone works already but edited the remaining (third) file. I have added MATE to the list of shown-in DEs: OnlyShowIn=Unity;MATE; After a reboot the new notification popped up where it is supposed to including all expected apps. ** Also affects: indicator-application (Ubuntu) Importance: Undecided Status: New ** Changed in: network-manager-applet (Ubuntu) Status: Confirmed => Invalid ** Also affects: ubuntu-mate-settings (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1754458 Title: nm-applet symbol not displayed on mate (18.04) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-mate/+bug/1754458/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs