How to fix web Connector QBWC1039 Error in QuickBooks?

QuickBooks error QBWC1039 can occur when the user tries to add a similar configuration file twice within the application. When the error occurs, it gives a mistake message- QuickBooks web connector error QBWC1039: There was an error adding the application. Check the QBWCLog.txt for details. Furthermore, the error message suggests, “Error Unique file ID required” followed by the error message.