Backups to Rackspace Cloud Files failing

Hi,

Backups to Rackspace Cloud Files have suddenly stopped working, error: [curl] 77: [url] https://lon.identity.api.rackspacecloud.com/v2.0/tokens

I cannot figure out what is causing this, are you able to make any suggestions?

Thanks in advance, j.

WordPress v4.0
PHP Version 5.4.32
PHP-FPM
allow_url_fopen = On
php_admin_value open_basedir {DOCROOT}/:{TMP}/

https://www.ads-software.com/plugins/backwpup/