When Avira Antivirus launches the scheduyled scan (Luke Filewalker), you get this error:
Avira Antivirus
Unknown error 857735165
Unknown error 857735165 is caused by Avira Antivirus updating the Luke Filewalker service and not being able to complete the update because it needs a restart.
To fix error 857735165, restart the computer then start the Avira Antivirus scan again.