After installing MS patches the permissions on ProgramData\Symantec\DataLossPrevention\DetectionServer\<DLP_version>\Pstlocalcopy folders are not the correct ones, causing a FileReader restart.

The following error can be found in the FileReader0.log


Feb 26, 2023 8:56:14 AM com.vontu.discover.FolderCustodian cleanupContents
WARNING: Failed to clean up folder D:\ProgramData\Symantec\DataLossPrevention\DetectionServer\15.8.00000\Pstlocalcopy. The folder no longer exists or permissions were revoked.
Feb 26, 2023 8:56:14 AM com.vontu.discover.FolderCustodian cleanUp
WARNING: Failed to delete folder D:\ProgramData\Symantec\DataLossPrevention\DetectionServer\15.8.00000\Pstlocalcopy
Feb 26, 2023 8:56:14 AM com.vontu.discover.FolderCustodian cleanupContents
WARNING: Failed to clean up folder D:\ProgramData\Symantec\DataLossPrevention\DetectionServer\15.8.00000\Pstdepositfolder. The folder no longer exists or permissions were revoked.
Feb 26, 2023 8:56:14 AM com.vontu.discover.FolderCustodian cleanUp
WARNING: Failed to delete folder D:\ProgramData\Symantec\DataLossPrevention\DetectionServer\15.8.00000\Pstdepositfolder

First check if the ProgramData\Symantec\DataLossPrevention\DetectionServer\<DLP_version>\Pstlocalcopy folders have the right permissions for the local protect account (Full access). If not, apply them. After applying the permissions, restart the services as per 159970 -Restart DLP Enforce services in the correct order.

The FileReader and all other services should start normally.  If not, recheck the FileReader.log for further troubleshooting.