The QuickBooks registration failure during the installation process can lead to Register QuickBooks Library Files Error. The message as a result of the error appears in the form, “ Error 1904 : [file path/name/ extension] failed to register.” Generally, the issue roots when the system has not been rebooted after performing the QuickBooks update. The damaged company file can eventually cause QuickBooks Error 1904 . In this article, we discuss the reasons behind Register QuickBooks library files error and how to resolve them with quick troubleshooting steps. Reasons behind Register QuickBooks Library Files Error There isn’t always a particular cause behind the appearance of Register QuickBooks Library Files Error. But, from the client cases, we have encountered, there are certain reasons that could trigger the error which has been listed below: The damaged company file is the general cause for Register QuickBooks Library Files Error. Damaged components. Incorrect Fil