Unable to start service 'firefox-sync'

I installed ffsync. I can not start it in services and getting the following error .
Unable to start service ‘firefox-sync’

Any idea ?

Hello,

Have you see the /var/log/ffsync.log, if there is some errors ?
I have installed ffsync too, but I don’t understand yet how to use it.

Hello
i have the same problem

it’s empty in /var/log/ffsync.log

file size 0KB
Owner: ffsync
group: root
permissions:-rw-r–r--

to use ffsync
https://yunohost.org/#/app_ffsync_en
see also
http://docs.services.mozilla.com/howtos/run-sync-1.5.html#running-the-server

Hi,
I’ve installed ffsync, and made the change in about:config in the line : identity.sync.tokenserver.uri (it’s not the same as said in the documentation).

Then it seems to work, but how could I know if it is effectively sincyng on my server and not on mozilla’s ?