User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:50.0) Gecko/20100101 Firefox/50.0 Build ID: 20161104212021 Steps to reproduce: I have tree custom settings that I want to sync between different firefox installations (I use a lot of virtual machines to test). Therefore I have added two three custom settings: services.sync.prefs.sync.browser.search.openintab=false services.sync.prefs.sync.browser.tabs.closeWindowWithLastTab=false services.sync.prefs.sync.browser.tabs.loadDivertedInBackground=true Actual results: When I create a new virtual box and install firefox and sign in with the profile two settings are synced, openintab and loadDivertedInBackground, but the closeWindowWithLastTab isn't synced and its value is "true". Expected results: The custom setting closeWindowWithLastTab should be correctly synced and its value should be "false" and not "true" (default value)

Thanks! We're tracking syncing more things in bug 1269548.

Since a few versions it is working.

(In reply to Aquila from comment #2) > Since a few versions it is working. That's odd, as I'm fairly sure we don't sync that preference by default. Is it possible that you created a local pref services.sync.prefs.sync.browser.tabs.closeWindowWithLastTab with a value of true?

yes I created the services.sync.prefs.sync.browser.tabs.closeWindowWithLastTab entry to sync it.