SAP Crystal Reports Server 2013, OEM Edition

Hi ,

while using the SAP Crystal Reports Server 2013, OEM Edition service we are getting an exception  while running the report.

but when I am using the desinger 2013  and verfiy it on the same data it can load it,

do you have an explanation for that ,  how can I add logs to the current service ? to see the internal exceptions

Thanks

Fade