You may encounter a data refresh for a PowerPivot workbook in SharePoint error due to issues with Perfomance Counters on the PowerPivot Analysis Services server. You may see the following error in the ULS log:
EXCEPTION: System.ComponentModel.Win32Exception (0x80004005): Access is denied at System.Diagnostics.PerformanceMonitor.Init()
This may indicate that the PowerPivot System Service does not have permissions to the Performance Counters on the server running PowerPivot Analysis Services. To fix the error, add the account running the PowerPivot System Service application pool to the Perfomance Log Users and Performance Monitor Users groups by going to Computer Management > Local Users and Groups > Groups
A different error you may see in the ULS log is the following:
The '\MSOLAP$POWERPIVOT:Memory\Memory Limit High KB' performance counter could not be found.
This means that the Performance Counters for PowerPivot have not been loaded. Check the Registry by running regedit.exe and look for the following key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSOLAP$POWERPIVOT\Performance\Disable Performance Counters
If it is set to 1, the Performance Counters for PowerPivot Analysis Services is disabled. Set the value to 2 to enable the counters.
If that does not fix the error, you may have to run the following commands in a command prompt to recreate the counters: