QuickBooks Error 15240 typically arises during software upgrades or payroll when the update process is halted by improper system time, firewall constraints, or corrupted data. This problem may prevent QuickBooks from correctly downloading updates. In order to fix it, settings must be changed, the internet connection must be confirmed, and QuickBooks components must be repaired for optimal functionality. For assistance with QuickBooks, call 1.855.738.2784.