Check the status of the PowerPivot Management Dashboard Processing timer job, which copies data from the usage data collection ...

Check the status of the PowerPivot Management Dashboard Processing timer job, which copies data from the usage data collection subsystem to the PowerPivot Management Data.xlsx file, to see if it has started failing. Check the SharePoint ULS logs for detailed error messages that might indicate the root cause. For more information about this rule, see http://go.microsoft.com/fwlink/?LinkID=208180