I am currently using Firefox version 42. I noticed that a new version 43 is available and wanted to update my Firefox. Traditionally i would simply navigate to the "About Mozilla Firefox" window, where Firefox automatically checks for a new version, downloads it and lets me install the update with a single click. However, when I open the About-window Firefox checks for a new version but insists my browser is up to date. I recognize the obious work-around of installing the new version manually. This issue has however plagued me since several versions ago. I always hoped it would work itself out after enough updates, but since it still persists today I wanted to seek the collective help of the Mozilla community. My system is Windows 10 (the error was also present during Windows 8.1) and I also use Thunderbird which updates itself just fine.