KB44872: "HTTP error encountered while trying to access a REST service. " error message appears while running XQuery report in MicroStrategy Developer 9.x

SYMPTOM:
The following error message appears while trying to access a REST server via XQuery report in Strategy Developer 9.x.

The following error occurs in pass 0: mstr-rest:post() failed. HTTP error encountered while trying to access a REST service.

Error type: XQuery Engine error. couldn't connect to host. Connection String: XQUERY;UID=Data;. Connection String: XQUERY;UID=Data;

 
CAUSE:
Proxy server is being used for the network connection. However, one possible cause is that the proxy address given in the Database Instance configuration is incorrect.
 
ACTION:
In the Database Connections configuration of the XQuery Database Instance, give correct proxy address in 'Additional connection string parameters' field.