NullPointerException when running scheduled report

I am getting the following error when running a scheduled report.  This is only occuring when running a report thru the schedule.  Otherwise the report is executing fine.  Please help.  Running JS 5.6 on CentOS.

java.lang.NullPointerException 
at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.executeAndSendReport(ReportExecutionJob.java:554) 
at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.execute(ReportExecutionJob.java:222) 
at org.quartz.core.JobRunShell.run(JobRunShell.java:213) 
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:557)