Gfilui

About three months ago, I noticed cinnamon randomly going to fallback mode; however, clicking "Restart Cinnamon" always worked in restarting it, and no errors seemed to be reported.

About two weeks later, I realized that it was every time I got a notification. It bugged me, but I just never used apps that sent me notifications (I never had enough time to look at it further).

Today, I've tried fixing it, and now I'm really aggravated toward the seemingly simple problem.

I've tried tons of solutions. I tried purging every notification-related app on the device, and then reinstalling each one directly from the repositories. Tried a notification from three apps, and they all crashed it. Rebooted, and same results.

I looked in the system monitor to find that the only notification-related app that was running was csd-print-notifications from /usr/lib/x86_64-linux-gnu/cinnamon-settings-daemon/csd-print-notifications.

So naturally, I wondered where notify-osd was, as it had seemed to be my default notification daemon in the past. I found it, reinstalled it, rebooted, retested, and all resulted in crashes once more, all of which could be recovered.

Also, during the tests, I had my phone synced to the computer using indicator-kdeconnect. The phone showed each of the notifications perfectly, while the computer crashed and showed none. This gave me the notion that while the notifications are somehow being transmitted, they just aren't getting far enough to reach cinnamon.

So in a terminal, I ran sudo su, and then /usr/lib/x86_64-linux-gnu/notify-osd &.

This started the daemon, and it showed up in the system monitor as being run by root, which is what I wanted. I tried sending the notifications once more, and all failed. However, I decided to add a fourth method for testing notifications.

In a new terminal, I typed notify-send test. To my surpise, Cinnamon did not crash! Unfortunately, however, it didn't show any notification, either. The only indication that a notification was send would be my phone picking up the notification.

And just to prove that kdeconnect wasn't interfering, I closed them out from the system monitor, and the notification failed with and without the terminal daemon.

An even more strange discovery is that when Cinnamon crashes, and goes to the MATE desktop, I decided to try sending a notification with the daemon still running. It showed up. So I stopped the daemon, and send another one. It worked again! Not to mention that when I send the notification, it started a new daemon with the owner being my user, not root. But why...?

So I tried one last thing. I logged out, and logged back in, thus exiting fallback mode back into the normal cinnamon interface. In the terminal, I tried running /usr/lib/x86_64-linux-gnu/notify-osd & without root permissions. It didn't terminate, but this is what it returned:

** (notify-osd:2689): WARNING **: Another instance has already registered org.freedesktop.Notifications

** (notify-osd:2689): WARNING **: Could not register instance

Mind you, there was never a notify-osd instance running unless I manually started one as root (according to gnome-monitor). It didn't show an instance of notify-osd when I started it without root. Despite the messages, I tried sending the notifications anyway to see what would happen. Of course, cinnamon crashes once again, and my phone beeps telling me that my computer has a new notification.

This seems extremely confusing to me, and somehow Notify-OSD isn't launching on startup/login. How can I make it do so? And if I did, would it solve the problem? How do I fix Cinnamon's notifications?

Is there any other info I need to attach?