Sync Option is not working

when trying to sync from live version and to live version .

getting -
An error has occurred. Check your Internet connection and try again.

Any ideas why >?

Can it be that for some reason you lost connection to the internet?
Can you add a screenshot of the error?
Was the site published at least once?

Hi , Yes the site was published in addition im getting - " The current site is in template mode. Please save it to modify data. " when im trying to add data to the regular database " although i’ve already saved and published.
please see screen shots. Thanks!