Forcing an extension to work with your version of Firefox

Courtesy of Windows Secrets (original article is here):

Uninstall the extension.

Download the latest version of the extension.

It’s really a ZIP file so rename it from Extension.xpi to

Unzip Install.rdf into the same folder as the .zip file.

Edit Install.rdf.

Find the line containing the word maxVersion. Change the number between the angle brackets to a number equal to or larger than your current Firefox version.

Save the file, then add it back into your file, overwriting the original Install.rdf.

Rename it from back to Extension.xpi.

Drag and drop the file into an open Firefox window.