Run the Misc User Utility
The SQL Update Misc User 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.
Select Signature Utilities > File Maintenance Utilities > Signature > SQL Update Misc User. Select Yes to the message confirming that you want to update the SQL misc. user.