Hello, everyone. I'm Jessie, and I work as a customer service representative. Certain users want to know if the 'QuickBooks Error 324' issue is caused by a number of factors? Yes. The cause of the 'QuickBooks Error 324' might be that the QuickBooks file must have undergone some sort of issues such as being corrupted. Any app that has not been installed completely. The registry of Windows has been corrupted. A virus must have attacked. The same name is selected in two distinct QuickBooks Online accounts.