You are getting the following errors in Change Summary emails:
“The error is: Failed to obtain last stored event. Error details: The file or directory is corrupted and unreadable.”
“Error generating report: System.IO.IOException: The file or directory is corrupted and unreadable.”
This behavior usually means that incorrect or not existing path is specified to store Audit Archive.
In Netwrix Auditor navigate to Settings –> Audit Archive and verify that the path to your audit data storage is correct.