I recently upgraded and had a few issues that I did not find solutions to online, but was able to eventually workout, I thought I would share.
My issue was after the upgrade, I did not see the network icon and could not connect to the internet. I was able to see that nm-applet was already running - and running nm-applet did nothing. I was able to manually run sudo nm-applet and connect that way, but it was fragile (couldn't run nm-applet & it seemed I needed to keep a terminal window open, nohup did work sometimes)
One thing I tried that felt important was the following:
- Upgraded to the latest version of network manager & network-manager-gnome (sudo apt update && sudo apt upgrade to just update everything)
- See what version was installed (sudo apt show network-manager and sudo apt show network manager-gnome)
- Capture all your current settings. I took screenshots.
- Download the packages online. I didn't find my versions on the ubuntu page, but did find them on pkgs.org which provided a download link on the ubuntu server, which I felt I could trust.
- sudo apt purge network-manager-gnome and sudo apt puge network-manager Watch what is uninstalled, I also "lost" network-manager-openvpn-gnome for example.
- Reinstall sudo apt install network-manager-gnome
- Reinstall other "lost" packages
This helped, but did not solve the problem all the way. It seemed to make things more stable. I also had to reset the panels. I believe the topbar panel was running some old config that was broken.
So I ran mate-panel --replace
I also preferred the "Traditional" panel setup that I thought was the default on 18.04, so I went to settings, mate tweak, then set panels to traditional.
During my debugging, I also deleted or edited ~/.config/autostart/nm-applet.desktop and /etc/xdg/autostart/nm-applet.desktop (also copies for the root user and the blueman copies). In my working setup, my ~/.config nm-applet file exists, but is empty and my copy in etc is the following:
[Desktop Entry]
Name=Network
Comment=Manage your network connections
Icon=nm-device-wireless
Exec=nm-applet
Terminal=false
Type=Application
NoDisplay=false
NotShowIn=KDE;GNOME;
X-GNOME-Bugzilla-Bugzilla=GNOME
X-GNOME-Bugzilla-Product=NetworkManager
X-GNOME-Bugzilla-Component=nm-applet
X-GNOME-UsesNotifications=true
X-Ubuntu-Gettext-Domain=nm-applet
I had some other issues - my application icons were gone and time was missing, but I am going to make separate posts for that.
Another benefit is that the first post of each topic created under that category is made into a "wiki" post; this allows relatively unprivileged forum-goers to edit your tutorials for grammar, technical accuracy and other such mistakes and missed opportunities. (Normally, only a moderator or the original poster of the topic can edit the first post; in the latter case, there is a time limit after which you may not edit even your own posts anymore, at least at low privilege levels.)