Symptoms

The following error mesage is reported during file system backup:

Unknown status (-1) returned from the data sanitization scanner. (\\ServerName\C$\Program Files\PostgreSQL\9.5\data\base\16393\17355)

and

The process cannot access the file because it is being used by another process. (\\ServerName\ADMIN$\System32\CatRoot2\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}\catdb -> E:\Buffer\buf\2\1_3219_15282)

Cause

File system backup set with Volume Shadow Copy and CyberSecurity options under Cybersecurity may report the above error for every single file it scans.

Workaround

You may uncheck the  option under Cybersecurity category called Perform cybersecurity scan but leave the Volume Shadow Copy on.