How do I get rid of this error?

I’ve got a clean install of CE v5 on our server. I can’t login to admin console as I get HTTP 500 errors - extract from logs below (this is repeated every time I try):
[30-Jan-2014 11:04:43 Europe/London] PHP Warning: SimpleXMLElement::__construct(): Entity: line 1: parser error : Start tag expected, ‘<’ not found in /opt/kaltura/app/admin_console/lib/Kaltura/Client/ClientBase.php on line 222
[30-Jan-2014 11:04:43 Europe/London] PHP Warning: SimpleXMLElement::__construct(): Thank you for using the Kaltura On-Prem Video Platform. in /opt/kaltura/app/admin_console/lib/Kaltura/Client/ClientBase.php on line 222
[30-Jan-2014 11:04:43 Europe/London] PHP Warning: SimpleXMLElement::__construct(): ^ in /opt/kaltura/app/admin_console/lib/Kaltura/Client/ClientBase.php on line 222

I guess there might be some configuring to do, to stop this message appearing at the XML parser, but nothing about it in the documentation - all help appreciated!
Thanks