Hello goos unfortunately the '''browser.download.manager.scanWhenDone''' preference not exist anymore, the above preference replaced from '''browser.safebrowsing.appRepURL''' preference in about:config. In order to change your Firefox Configuration please do the following steps : # In the [[Location bar autocomplete|Location bar]], type '''about:config''' and press '''Enter'''. The about:config "''This might void your warranty!''" warning page may appear. # Click '''I'll be careful, I promise!''' to continue to the about:config page. # copy the next bold '''browser.safebrowsing.appRepURL''' and paste it in the about:config page search field # now you can see that preference (name, status, type value), double-click on it and you have a box with the name "Enter string value" # clear everything in that box (delete it with delete key) and click ok. # exit firefox and restart it. # check if your download list works. note also that the above steps disables application reputation checks but leaves other Safe Browsing malware protection intact. thank you