Error message when you export or delete entities in Microsoft Dynamics CRM 4.0: “An unhandled exception occurred during the execution of the current web request”

SymptomsWhen you export or delete entities in Microsoft Dynamics CRM 4.0, you receive the following error message: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.Details: Exception of type ‘System.Web.HttpUnhandledException’ was thrown.Stack trace:[NullReferenceException: Object […]