Right. So the issue is here:
ed Nov 23 17:03:02.153459 2016] [:error] [pid 19267] [client 10.20.0.202:42913] PHP Warning: SimpleXMLElement::_construct(): Entity: line 1: parser error : Start tag expected, '<' not found in /opt/kaltura/app/adminconsole/lib/Kaltura/Client/UserService.php on line 179, referer: http://xxxxxxxmyhostxxxxxx.fr/admin_console/
[Wed Nov 23 17:03:02.153558 2016] [:error] [pid 19267] [client 10.20.0.202:42913] PHP Warning: SimpleXMLElement::_construct(): REMOTEADDR header invalid signature in /opt/kaltura/app/admin_console/lib/Kaltura/Client/UserService.php on line 179, referer: http://xxxxxxxmyhostxxxxxx.fr/admin_console/
[Wed Nov 23 17:03:02.153574 2016] [:error] [pid 19267] [client 10.20.0.202:42913] PHP Warning: SimpleXMLElement::_construct(): ^ in /opt/kaltura/app/adminconsole/lib/Kaltura/Client/UserService.php on line 179, referer: http://xxxxxxxmyhostxxxxxx.fr/admin_console/
What's the value for remote_addr_header_salt in /opt/kaltura/app/configurations/local.ini?