No DATA in the Report generated by OPMANAGER (Availability report)

No DATA in the Report generated by OPMANAGER (Availability report)

Hi,
      Would like raise and issue regarding with one of the scheduled reports being generated by OPMANAGER. Lately, it doesn't have any data written on the report. No data available for yesterday and today's report. This schedule of this report is every 1am.  Please assist us in investigating the cause and how to resolve this issue. This is very critical to us.
 
Thanks