icloud for windows Outlook setup fails

Outlook 2013 setup fails with "incorrect username or password".

I am attempting to sync calendars on an iphone with outlook 2013 running on a windows 8.1 laptop via icloud. It use to work but now doesn't. I uninstalled icloud for windows and downloaded it and reinstalled. Then ran icloud for windows, hit apply and the outlook set up started. But this failed with incorrect username or password. Signed out and then in again as suggested by the message. Same problem. Logged on to icloud with the browser ok, so the username/password is correct.

Anyone know a solution please. Or perhaps an alternative way of sync'ing calendars (not via cable).

Thanks