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. Xsquizzit Accounting Connector give you tool to remove lock file. Please follow the below mention mitigation steps to remove the lock file.

http://docs.prod.xsqit.com/Connector/Connector%20Adaptor%20MYOB%20Premier-Enterprise%20(version%208.5-19.7).html" target="_blank">Mitigation Steps