Please update to 57.0.2 https://support.mozilla.org/en-US/kb/update-firefox-latest-version

Old extensions/addons still exist but they are disabled due to incompatibility. https://support.mozilla.org/en-US/kb/disable-or-remove-add-ons

Looking for replacements : https://addons.mozilla.org/en-US/firefox/extensions/ and https://mozilla.github.io/extension-finder/

fyi : https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/

Please let us know if this solved your issue or if need further assistance.

Thanks for the info. But I already did the update. That is what caused the problem. Firefox does not just show my extension browsers like Dogpile and Metacrawler as disabled, it no longer shows them at all, even though they must still be on the computer keeping me from reinstalling. I went through the info. that you gave me and I am sorry If there is a solution there I am not technically proficient enough to find it.

Hi Neophyte2, do you mean extensions or search engine plugins?

Extensions

The old extensions which are incompatible with Firefox 57 may appear on a separate list on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. Then on the right side, check near the top for a "Show Legacy Extensions" link.

Sometimes there will be a helpful "find a replacement" button for a legacy extension that gives you a specific recommendation; other times, you may get a general search link.

Search Engine Plugins

Are they still visible on the Search panel of the Options page? Either:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the left column, click Search. Then on the right side, you have controls to select the default search engine, and a box with available "one off" buttons. If there isn't a check mark next to the search sites you want to use, click in that space in the left column to unhide them.

Does that help?

Sorry, I thought they were the same. But they are not visible on the search panel of the Options page. And when I go to the Add-ons page and then click Extensions I can not find a "Show Legacy Extensions Link. There is a general search link but if I type in "browsers" I still get nothing.

Thanks,

Neophyte2

I don't think add-ons related to Dogpile and Metacrawler would be called browsers. Those are meta-search websites.

Where did you go to try to reinstall them -- where you got the message that you had them already. Could you give the links to those pages?

OK, I am a little smarter now. I found one on the add-on page and it is a search engine plug-in. The problem is that if I attempt to install it from the Firefox add-on page where I found it I get a message that says this file already exists. But the file still doesn't show up by going to add-on in settings menu.

Well the problem has been solved. I just found these search engine plug-ins on Firefox under Options---Search---One-Click Search Engines. My thanks to the people who tried to answer my question. They helped by showing me places to look that I would not have thought of.

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, ***please select the answer that solves the problem***. This will help other users with similar problems find the solution more easily. Thank you for contacting Mozilla Support.