QuickBooks Error 9999 can be a confusing error to encounter. It usually means that the user has not entered any transactions into the software and is trying to create one and it doesn't want to let them do so. The most common cause of this error is that the company's file has been corrupted and QuickBooks won't let users back up or save their data in case something goes wrong. QuickBooks error 9999 can be fixed by running a recovery cycle and determining whether or not it was successful.