How to Fix Returning NULL QBWinInstance Handle Error in QuickBooks

An Unexpected Error has Occurred in QuickBooks the Mainframe Must be Already Created by Now as This DLL is Demand-loaded

An Unexpected Error has Occurred in QuickBooks: the Mainframe Must be Already Created by Now as This DLL is Demand-loaded [FIXED]

by James Richard
August 15, 2024August 15, 2024

The “An unexpected error has occurred in QuickBooks: the mainframe must be already created by now as this dll is demand-loaded” error message can show up when QuickBooks cannot connect with the Integration Manager. This error can occur due to… Read More »An Unexpected Error has Occurred in QuickBooks: the Mainframe Must be Already Created by Now as This DLL is Demand-loaded [FIXED]