An object reference to an instance of a class that implements the Progress.Lang.Error interface. The instance describes an ERROR
        condition raised by an asynchronous call to a procedure or Web service operation. This
        attribute holds the Unknown value (?) if there is no ERROR
        or relevant STOP condition.
      Note: If the object reference is to an instance of Progress.Lang.StopError, it describes a STOP condition raised from an unexpected
        error in the asynchronous call, not an ERROR condition itself.
      Data type: Class that implements the Progress.Lang.Error interface
      Access: Read-only
      Applies to:
        Asynchronous request object handle
      The error or stop object the attribute references can be thrown by the
        server or raised in the client before anything is run on the server, for example, if there
        is an error in processing one of the parameters.
      Compared to the ERROR-STATUS system handle , ERROR-OBJECT can
        accommodate user-defined error objects, thereby providing more information to the
        client.
     
    Notes
      
      
        - Stop object support is available as a Technology Preview only in OpenEdge Release
          11.7.
- Error objects can be thrown by the server:
            - From an error CATCH block
- Using the ROUTINE-LEVEL ON ERROR UNDO, THROW directive
- Using a Progress.Lang.AppError
              object that is created as a result of a RETURN ERROR in the called procedure
 
- StopError objects can be thrown by the server:
            - From a stop CATCH block
- Whenever the server does not handle the corresponding STOP condition
              and the client has a relevant CATCH block on its portion of the call stack
 
- If a StopError object is thrown from the server, its
          error messages continue to be available on the client from the serialized object even
          though they are written to the log file on the OpenEdge application server.