Suppose your QuickBooks GUI will not open. In that case, you can clear the QuickBooks cache, run the program as an administrator, check your internet connection and firewall settings, update QuickBooks and your system, or try the web version of QuickBooks. Some users report an issue where the QuickBooks graphical user interface fails to open, often accompanied by an error message. If it stops working, QBDBMgrN not running on this computer may fai...