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!

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

Preview no longer works when I pass mouse over image in Persona add-ons

more options

Before when I would hover my mouse over the images in the add-on themes (Personas for FireFox) it would change the image at the top of my browser so I could see what it would look like before I set it as background. Now, I get no preview at all and I have to actual set it as the background in order to see if I want it or not.... a very tedious and time consuming process. What happened? Why can't I see a preview anymore? Can I fix this? Thank you for your help!!!

Before when I would hover my mouse over the images in the add-on themes (Personas for FireFox) it would change the image at the top of my browser so I could see what it would look like before I set it as background. Now, I get no preview at all and I have to actual set it as the background in order to see if I want it or not.... a very tedious and time consuming process. What happened? Why can't I see a preview anymore? Can I fix this? Thank you for your help!!!

Chosen solution

Previewing a lightweight theme (Persona) only works on sites that are white-listed via an allow exception, so make sure to have an allow exception for the addons.mozilla.org domain. You can see the permissions for the domain in the current tab in:

  • Tools > Page Info > Permissions > [X] Install Add-ons

You can reset these prefs on the about:config page via the right-click context menu to the default value to restore the default software exceptions for installing add-ons from the Add-ons website. xpinstall.whitelist.add (addons.mozilla.org) xpinstall.whitelist.add.180 (marketplace.firefox.com)

If these prefs do not exist or are an empty string if you open the exception window then the corresponding default entry is recreated.

  • Tools > Options > Security : "Warn me when sites try to install add-ons": Exceptions
Read this answer in context 👍 6

All Replies (2)

more options

Chosen Solution

Previewing a lightweight theme (Persona) only works on sites that are white-listed via an allow exception, so make sure to have an allow exception for the addons.mozilla.org domain. You can see the permissions for the domain in the current tab in:

  • Tools > Page Info > Permissions > [X] Install Add-ons

You can reset these prefs on the about:config page via the right-click context menu to the default value to restore the default software exceptions for installing add-ons from the Add-ons website. xpinstall.whitelist.add (addons.mozilla.org) xpinstall.whitelist.add.180 (marketplace.firefox.com)

If these prefs do not exist or are an empty string if you open the exception window then the corresponding default entry is recreated.

  • Tools > Options > Security : "Warn me when sites try to install add-ons": Exceptions
more options

Thank you so much for helping me!