Keep Getting An Error Message When Trying To Complete A Task Form In Nintex Workflow

ISSUE

When completing a Nintex Task Form associated with a Nintex Workflow, SharePoint displays the error message "Unexpected error occurred."

ERROR CODE

From the GUI: Unexpected error occurred. If the problem persists, contact your support team with the following information: Correlation ID: xxxxxx Tenant ID: xxxxxx Time (UTC): YYYY-MM-DD HH:MM:SS From Logs: - Task Outcome Control 'outcomeCtrl' is not found in form - Nintex.Forms.SharePoint.Exceptions.UserException: Error in task. Input string was not in a correct format. - Exception caught by error page. => Nintex.Forms.SharePoint.Exceptions.UserException: Error in task. Input string was not in a correct format. - Application_Error => System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown.

RESOLUTION

Make sure the task form has the "Task Outcome" control present or SharePoint will throw an error message when closing the form.