Is it an error displayed by the Flash player plugin? I see numerous references to this error number on Adobe's forums, but haven't gone to read them yet: https://www.google.com/search?q=error+2046+site:forums.adobe.com

By the way, your "More System Details" to the right of your post shows a very old version of the Adobe Acrobat plugin. You might not use Adobe Reader/Adobe Acrobat very often, but because older versions have numerous security issues, it would be a good idea to update. The best way is, inside your Adobe product, use the Help menu, then Check for Updates. Once the Adobe installer finishes its work, Firefox should find the updated plugin the next time you start it up (or possibly sooner).