I have installed the latest version of Firefox 48 and after a period usually less than 24 hrs If I reinstall the firefox 48.dmg file it will report "a newer version of Firefox.app already exists" Their is no new version of Firefox 48 for Aug-16-2016. This issue also occurs for the Tor browser. Firefox is continuosly running when the version change occurs. Reinstalling requires shutting down Firefox. I suspect it is a Firefox hack or possibly Yosemite OS problem. Does anyone have any ideas?