Websites, like the Firefox add-on website, use your user agent string to determine what browser you are using. It contains information about the browser, operating system and version that you are using. According to your system information that you submitted to this forum, your user agent appears to be changed by a program called '''Abelssoft'''. Changing the user agent string can give you the benefit of slightly better privacy, but it does break certain functionality. In this case, it looks like the Firefox add-ons website is being told by your user agent string that you are using a different browser. See the [[How to reset the default user agent on Firefox]] page for more information on how to reset your user agent back to the default. Hope this helps.