This add-on was disabled due to not being a WebExtension. Legacy add-ons no longer work as of Firefox 57. For more information see: https://support.mozilla.org/en-US/kb/firefox-add-technology-modernizing

To find a replacement for your legacy add-on try this helpful website: https://mozilla.github.io/extension-finder/

If this solved your problem, mark this reply as the solution.

Thank you for the quick reply. What is the name of the add-on? I need it to search the extension finder. Thank you.

Copy/paste about:addons into the Address Bar and then Enter. Click Extensions on left. Click the banner at page top in the white still : Missing something,,,,,,,,Show Legacy Extensions.

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

I'm a dummy. I tried copying and pasting "about:addons" into the address bar of the Extension Finder and got nothing. Please help. Thanks.

no......please read  : Copy/paste about:addons into the Address Bar and then Enter

Click Extensions on left. Click the banner at page top in the white still : Missing something,,,,,,,,Show Legacy Extensions.

Here are the other ways to access 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 above the list look for a link to Show legacy extensions. If you have that link, go ahead and click it.

Also, I'm not sure I understand what this add-on did. Was it capturing a rectangular image, or was it copying the text? To copy text, you can use the built-in methods, such as:

• Ctrl+c
• right-click > Copy

If it was capturing a screenshot, you could try the Firefox Screenshots add-on, which may already have been installed. More info: Take screenshots in Firefox.