Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

I installed Linux. It came with FF.

  • 1 reply
  • 1 has this problem
  • 2 views
  • Last reply by cor-el

Goldmoons.Tavern
Goldmoons.Tavern
more options

I had been using FF prior to installing a single boot Linux Mint 19.2 Cinnamon Tina. I went from Linux Lite to Mint. When I opened the freshly installed FF and pressed "sync now" it restored all of my add-ons. All of the files were there. All thumbnails too. Now, when I go to Customize and click on the themes menu, I do not see any thumbnails of the downloaded themes except for the 3 default themes that come with FF. I also am unable to mouse over those 3 themes and have them display what they look like real-time. When I click on manage themes (and I have many), there are no thumbnails. When I right click and ask to view the image it gives me the following error: 

Firefox can’t find the file at jar:file:///usr/lib/firefox/omni.ja!/chrome/toolkit/content/mozapps/extensions/null.

Everything was functioning properly until yesterday. So a total of 3 days. How can I resolve this?

I had been using FF prior to installing a single boot Linux Mint 19.2 Cinnamon Tina. I went from Linux Lite to Mint. When I opened the freshly installed FF and pressed "sync now" it restored all of my add-ons. All of the files were there. All thumbnails too. Now, when I go to Customize and click on the themes menu, I do not see any thumbnails of the downloaded themes except for the 3 default themes that come with FF. I also am unable to mouse over those 3 themes and have them display what they look like real-time. When I click on manage themes (and I have many), there are no thumbnails. When I right click and ask to view the image it gives me the following error: Firefox can’t find the file at jar:file:///usr/lib/firefox/omni.ja!/chrome/toolkit/content/mozapps/extensions/null. Everything was functioning properly until yesterday. So a total of 3 days. How can I resolve this?
Attached screenshots

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

See:

  • resource://gre/chrome/toolkit/content/mozapps/extensions/

You can try the Firefox version from the official Mozilla server if you currently use a version from the repositories of your Linux distribution.