Taskbar constantly disappearing, Alt-F2 r over and over to restore it

I decided to try Zorin Core a couple of months ago and it is good for the most part but my taskbar constantly disappears when I step away from the computer for a bit. The system is not going into sleep, just turning off the screen when idle.

The first few times I rebooted to fix it, then I found other topics with this problem including Alt-F2 and enter r to restart the shell. This works to restore it but it is annoying to have to restart the shell over and over during the day.

A bug fix for this issue was noted on this topic in Jun '21, but others have reported the same problem since:

Panel Intellihide is turned off in my taskbar settings. I tried turning it on to see if it would help, but it didn't. Any suggestions what to try next?

Hi, and welcome!

In that same thread you linked to the last reply suggests disabling all other gnome extensions, and test again to rule out any conflicts between extensions. Did you try that?

Hi zenzen, thanks for your reply.

I did notice that suggestion, but there isn't an Extensions option in my Zorin Settings and no Gnome Tweak Tool installed either. I haven't added any extensions that I know of.

You will need to install the extension manager from the software store and GNOME Tweaks from the terminal (Ctrl + Alt + T)

sudo apt install gnome-tweaks

Ok, I installed both of those. Not sure what I am supposed to be looking for, they look like they only have default extensions that came with Zorin?

Extension Manager has the following turned on in Integration:
Run in background
And one item in Default Handlers, gnome-extensions.links

Tweaks has the following turned on:
Suspend when laptop lid is closed

Nothing in Startup Applications

Or is there somewhere else I should be looking?

Look for the Zorin Menu extension in the Extension Manager and try re-enabling that.

I don't see anything called Zorin Menu in Extension Manager. This is a pretty stock Core install that I have not modified much if at all. This is all I see:

I think you've got a different extension manager. This is what it should look like:

Interesting. I installed the #1 and only result when I searched for Extension Manager in the Zorin Software store. How do I find the right one?

Does the source of the app say Flathub (dl.flathub.org)?

Yes, this is what I see:


Ah, apparently there is a different way to launch it that gives a different interface. I was running it from the item in Settings, but when I click Launch in the Software Store I see this, Zorin Menu is already enabled:

I get it now, the listing in Settings is the settings for this Extensions Manager app, but I had to run the actual app to see the list. I have not added any extensions.


Now that that's solved, I mentioned that you should try disabling then re-enabling the extension.

Also, if you could take a note of what windows was focused before this issue happens that would be helpful. I've read a few reported issues and it seems that most people had something maximized or in full-screen mode.
Maybe Firefox playing a video or something?

There's also a way that may give some additional information, again based on what I've read online so I'm not sure how relevant that may be. When this issue happens again try the following:

  1. Press Alt + F2. Type "lg".
  2. Go to the "extensions" tab.
  3. Locate the extension Zorin Taskbar.
  4. Click on Show Errors.

Nothing maximized or full screen.
It just disappeared again when I stepped away for a few minutes, this Firefox browser window was focused. I have definitely had it happen with nothing focused though too.
I tried Alt + F2 and lg, enabled errors, it says "this.monitor is null"

I'll try disabling and re-enabling Zorin Menu and Zorin Taskbar next...

Unfortunately disabling/re-enabling those did not help, it just happened again.

I had the idea to check /var/log and found the following error in syslog. Wild guess - is zorin-taskbar crashing when my monitor goes into power save or something like that?

gnome-shell[1603]: JS ERROR: Extension zorin-taskbar@zorinos.com: TypeError: this.monitor is null#012getPosition@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/panel.js:505:24#012_init@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/panel.js:108:29#012_createPanel@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/panelManager.js:417:17#012enable@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/panelManager.js:81:34#012_enable@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/extension.js:95:18#012enable@/usr/share/gnome-shell/extensions/zorin-taskbar@zorinos.com/extension.js:64:5#012_callExtensionEnable@resource:///org/gnome/shell/ui/extensionSystem.js:170:32#012_enableAllExtensions/<@resource:///org/gnome/shell/ui/extensionSystem.js:612:22#012_enableAllExtensions@resource:///org/gnome/shell/ui/extensionSystem.js:611:37#012_sessionUpdated@resource:///org/gnome/shell/ui/extensionSystem.js:639:18#012_emit@resource:///org/gnome/gjs/modules/core/_signals.js:133:47#012_sync@resource:///org/gnome/shell/ui/sessionMode.js:198:14#012popMode@resource:///org/gnome/shell/ui/sessionMode.js:166:14#012_continueDeactivate@resource:///org/gnome/shell/ui/screenShield.js:550:30#012deactivate/<@resource:///org/gnome/shell/ui/screenShield.js:541:44#012finish@resource:///org/gnome/shell/gdm/authPrompt.js:558:13#012finish@resource:///org/gnome/shell/ui/unlockDialog.js:870:26#012deactivate@resource:///org/gnome/shell/ui/screenShield.js:541:26#012_onUserBecameActive@resource:///org/gnome/shell/ui/screenShield.js:342:18

I've definitely seen that message of null monitor somewhere in those bug reports, so it may be related. I'll have to look a bit more into it.

Are you on a laptop, and are you using external monitors? If yes, has this happened while you were not using the external monitors?

No, this is a desktop system with a single monitor.

This sounds a great deal like an extension is corrupted and is crashing the shell.

You might try:

sudo apt install --reinstall gnome-shell-extension-zorin-taskbar gnome-shell-extension-zorin-dash gnome-shell-extension-zorin-menu

I don't think the extension is written for power state changes to a physical device. When the monitor sleeps, the taskbar extension doesn't see the monitor and crashes.

A possible fix would be a shell script that runs when the monitor returns and refreshes the DE.

You may be able to modify the js file that handles this to also refresh the interface, instead of a shell script, but I'd have to look at that and see if it changes anything else.