When the system becomes unstable, QuickBooks error 1904 occurs, causing critical files to disappear. If your system is not properly maintained, this will continue to happen. Solution Of QuickBooks error 1904 1- Install and run the QuickBooks Diagnostic Tool 2- Correct the Windows components 3- Change the permissions of the user from the security settings Make sure you are logged in as Windows Administrator User Permissions: How to Change Them 4- Repair a current QuickBooks installation 5- You need to fix a current QuickBooks establishment 6- Update the Windows and download the missing updates