Blank System Tray icon in Panel
 

Over the past few weeks, I’ve noticed what looks like a black, but blank icon in the system tray – see the attached image. It’s the furthest left icon (to the left of the alarm clock image).
When I look in Applets I’ve narrowed it down to the System Tray applet itself. The applet says that it “hosts all the system tray icons”.

It isn’t the end of the world by any means, just a little irritating. As I said, it’s only started appearing recently, but don’t know if there’s some way to prevent it being displayed? Or failing that, can I change its colour to be the same as the rest of the panel perhaps (whatever the icon colour needs to be set as)?
If there are any suggestions, please try to keep it at a “Dummmies basic level”, as a newcomer to Linux from Windows.

Hi paxolin. What do you get if you right-click on the icon? Failing that, double-click?

Hi hydrurga,
Assuming you mean clicking normally (without going into edit mode or suchlike) both have no effect at all.

Ok, can you right-click on a blank area of the panel, then click on Troubleshoot, then Looking Glass.

Click on the Extensions tab and see if you can account for all the extensions listed there.

Also click on Log and see if there are any errors or warnings that might indicate the problem.

To close the diagnostics window, click on Actions on the bottom right and then Quit.

I followed your precise instructions, this is the result. See the two attached screenshots.

The only items I think it could possibly be is one of these:
Panel launchers
Window list
System Tray

As for errors in the log file, I’m afraid that’s way out of my understanding, but I’ve attached an image if the three (pairs of?) errors, if they mean anything to you.

Thanks. Your knowledge is about as much as mine at this point.

From the error log, it looks as if a system tray icon has been deleted but refuses to go quietly. Did you try to remove an icon or delete a package just before the problem began?

Your icons appear to differ from a standard install in that you don't have the User Applet, Removable Drives, Power Manager or Windows Quick List applets loaded - perhaps it was one of these you removed?

Anyway, my only suggestion (with my limited knowledge) is that you try a Troubleshoot->Restore all settings to default and see if that makes a difference. You might be advised to make a system backup first. You may also have to reboot afterwards so that the applications you have installed with system icons get the chance to reload those icons in the panel.

Another successful suggestion hydrurga, thanks. I did a restore to default.
Then one by one added the personalised applets I had before, including deleting some default ones, to get it back to how I had it before restoring.
I've rebooted a few times and it's all fine now. Thanks again.

Great to hear!

As the OP, I thought this issue was resolved, but the symptoms reoccurred later. I persisted, and eventually discovered it was KeePass2 causing the blank icon.

After contacting one of the people involved in the development of KeePass2 (David Lechner) I was pointed in the direction of plug-in which has definitely resolved the issue. I now have a KeePass2 icon instead of the blank one.

In case anyone else wants to know about this, have a look here: https://github.com/dlech/Keebuntu specifically “keepass2-plugin-tray-icon”

Thank you for posting the solution. That is good information.
Please edit the thread title to include [SOLVED]