I get a warning when trying to use a mindmap:

Network error: cannot connect to site: […]=services/amfphp
Details: wrong connection info (url) or missing AMFPHP library or wrong AMFPHP|Services version or wrong Services authentication method (only Session auth needs)

Msg: [FaultEvent fault=[RPC Fault faultString="Send failed" faultCode="Client.Error.MessageSend" faultDetail="Channel.Connect.Failed error NetConnection.Call.Failed: HTTP: Failed: url: '[…]=services/amfphp'"] messageId="19EC2F6F-B433-9965-439E-B70FF0BB2204" type="fault" bubbles=false cancelable=true eventPhase=2]

I've tried looking for instructions for installing extra libraries or anything, but I can't find any pointers.
Is this a server configuration thing, or am I missing a library?