Cannot find dispatch method for [url]

I have formulated a custom SOAP request body for calling a web service. But when i call the web service from a micro from a page. The following error comes.

*

> com.mendix.modules.microflowengine.MicroflowException:
> javax.xml.ws.soap.SOAPFaultException:
> Cannot find dispatch method for
> {http://www.ris.eu/nts/3.0/}get_messages_query
>     at
> DisruptionHandler.nts_NtS_message_service_service_get_messages
> (CallWebservice : 'Call web service
> 'get_messages'') Advanced stacktrace:
>     at
> com.mendix.modules.microflowengine.MicroflowUtil.processException(MicroflowUtil.java:143)
> Caused by:
> com.mendix.systemwideinterfaces.MendixRuntimeException:
> javax.xml.ws.soap.SOAPFaultException:
> Cannot find dispatch method for
> {http://www.ris.eu/nts/3.0/}get_messages_query
>     at
> com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:36)

*

I am not sure why is that.? Can you please tell me what could be the problem. Below is my custome service request body.

<nts:get_messages_query xmlns:nts = "http://www.ris.eu/nts/3.0/">
<nts:message_type>FTM</nts:message_type>
<nts:ids>
<nts:id>NLKAM0084D0440700073</nts:id>
</nts:ids>
</nts:get_messages_query>