The SQL Update Misc User utility Utility creates a miscellaneous user on each database, including Dynamics. This miscellaneous user enables actual users to work with Document Attachments; however, there is no associated login. The miscellaneous user is used by the system only.
Choose Signature Utilities > File Maintenance Utilities > Signature > SQL Update Misc User. Choose Yes to the message confirming that you want to update the SQL misc. user.