Using FF 44.0.2 for Linux Mint. Attempting to add user agent overrider from add ons site has error: "The add-on downloaded from this site could not be installed because it appears to be corrupt.
It maybe a network problem when you downloading from AMO. Have you retry it? Or you can download the .xpi file to harddisk, then use arcihve tools(like unzip/7z) to extract it, check the .xpi file integrality.
Using FF 44.0.2 for Linux Mint. Attempting to add user agent overrider from add ons site has error: "The add-on downloaded from this site could not be installed because it appears to be corrupt.