Well, this is the error that generally occurs when the user is trying to open the new updated version of QuickBooks. QuickBooks Error 15221 makes the user unable to use the QB software and sometimes also affects the working of the computer. If you are facing such error you can take the help of a technician, who has complete knowledge about such error. The error can hamper your work. So, before it makes things worse for you, connect with a QuickBooks expert.