When an Excel file is opened and locked by a user and other users attempting to open the same file will encounter the following error. This KB explains how to identify the user who has the file open. ...When an Excel file is opened and locked by a user and other users attempting to open the same file will encounter the following error. This KB explains how to identify the user who has the file open. The popup error shows 'another user' as the application locked account (Microsoft Excel), which does not always match the account used for CIFS access. The account used for CIFS access can be found using the method described in the Procedure section with ONTAP commands.