A common cause for this message is the presence of 'lock files' in the location where the company file is stored. These files are created by the system during an MYOB session to manage multi-user. Ordinarily these files are automatically deleted when the session ends, but an abrupt termination of a session can result in one or more of these files remaining in the system.
To rectify this the lock files must be deleted.
1. Ensure all users are logged out of MYOB.
2. Using Windows Explorer, search for any files with an extension of *.FLK in the location of your company file.
3. Delete selected .FLK files.