When the program installation fails because of missing or corrupted Microsoft.NET Framework components, QuickBooks Error 1642 appears. QuickBooks may not open or update correctly due to this problem. In order to fix it, you usually need to run the QuickBooks Install Diagnostic Tool, fix or reinstall the.NET Framework, and make sure your system satisfies software requirements. If you require expert assistance with QuickBooks, give 1.855.738.2784 a call.