Hello, folks! My name is Alex. I have 6 years of experience in resolving QuickBooks queries and errors. The QuickBooks error 61 may occur due to two major reasons. First, when there is an issue with the setup of the application. Next, when there is an issue with the framework or the registry of the windows. This is a deadly error because not only does it affect the QuickBooks bit also affects the Microsoft office and mac applications when the system hardware is broken for some reason.