Locked File Errors QuickBooks Desktop
https://www.wizxpert.com/locke....d-file-errors-quickb

Locked file errors QuickBooks Desktop files are usually due to someone else being in the company file or a problem accessing the permissions for the company file. Typically, locked file errors imply you cannot access the company file, or may leave portions of an operation you are trying to do on the company file from not working. Some reasons why you will see locked file errors are due to trying to access the company file with more than one user, if the file is open on another system, a corrupt company file, or more users than are available. A locked file error can usually be removed by verifying that there are no other users in the company file, by checking if the company file is open on another instance of QuickBooks, or by checking File Permissions on the company file.