After DAOS has been enabled on a Domino server, if the virus scanner has not been configured properly to avoid .NLO files, "File is in use" errors may occur.
The virus scanner should be configured to prevent processing the. NLO files in the DAOS repository. This can be accomplished either by specifying that the scanner skip files with an .NLO suffix, or by specifying that the DAOS base directory (and all subdirectories) should be skipped by the scans.
Instead of scanning the .NLO files directly, the attachments should be scanned via the Domino server by an application, such as an add-in program, that works through the Domino API.