ERROR - ProxyService Error reading from wsdl URI

$subject could be a common error for many new ESB users - so, thought of keeping a note here.

This could easily happen if you create a proxy service against the sample echo service which ships with WSO2 ESB - and WSDL was pointed with an URI - and the corresponding WSDL is unavailable at the time proxy service been deployed [i.e. When the ESB is restarted]

<publishWSDL uri="http://localhost:8280/services/echo?wsdl"/>

To recover from this error - you need to edit the file [ESB_HOME]/repository/conf/synapse-config/proxy-services/your_service_name.xml and add the following parameter..
<proxy name="test" transports="https http" startOnLoad="true" trace="disable">
        <parameter name="enablePublishWSDLSafeMode">true</parameter>

Now restart the ESB and you will notice that this particular proxy service is not loaded - but the ESB starts fine.

To handle this issue in a more generic way - a fail-safe mode to be introduced in to the upcoming release of WSO2 ESB - further details here...