In essence, QuickBooks error 1406, also known as QuickBooks install error 1406, is an installation error that appears suddenly while you are using QuickBooks for accounting tasks. When a conflicting third-party program is running in the background, you may encounter this problem. This issue may prevent you from using QuickBooks procedures effectively. When attempting to update the QuickBooks program, this issue may also occur. You might also experience this issue if the Windows registry has specific damage.