When it comes to accounting, QuickBooks is known as the best accounting software that has been adopted by numerous small to mid-sized businesses. Unlike other windows, software QuickBooks also encounters errors while operations which can be resolved quickly with proper troubleshooting instructions. One of such error is the Event id 4 error that arises when the user launch (QBi) QuickBooks Integration Manager. The error message “Integration Manager could not connect to QuickBooks. Please make sure that it is open” is displayed to the user. Another error message that the a user notice is “QuickBooks Event ID 4 – An unexpected error has occurred in “QuickBooks”: Returning NULL QBWinInstance Handle” under Windows Event Viewer.