Error Message :
unexpected response
A Java SAP System is used without ABAP Components. An error occurs when attempting to load a Job definition from SAP.

Investigation
The Agent log shows:20160928/104408.497 - U2004172 Error while calling function module 'RFC_SYSTEM_INFO'
20160928/104408.497 - Destination XXX was changed. Refresh the destination instance with the JCoDestinationManager.
20160928/104409.513 - U2004172 Error while calling function module 'RFC_SYSTEM_INFO'
20160928/104409.513 - Connect to SAP gateway failed