Problems synching in EndnoteX7

This week my Endnote X7 is telling me it can’t synch and keeps stopping me putting in citations when I’m working on an assignment with a message;

‘Endnote could not connect to the online synch service.  This may be due to a temporary internet or server error. Please try again’

It was synching fine before so wondered if this was a problem with Endnote. But just in case I’ve re-entered my  email and password in the Preferences/edit/synch area but it hasn’t changed anything.

Any ideas what I should do? Thanks!