ORA-16878
        master observer cannot be stopped
        
        
        Cause
        The master observer cannot be stopped when another observer is registered.
        Action
        Use the SET MASTEROBSERVER command to establish another observer as the master observer. Then use the STOP OBSERVER command to stop the former master observer.
        
     
    
    
        ORA-16878
        master observer cannot be stopped
        
        
        Cause
        The master observer cannot be stopped when another observer is registered.
        Action
        Use the SET MASTEROBSERVER command to establish another observer as the master observer. Then use the STOP OBSERVER command to stop the former master observer.
        
     
    
    
        ORA-16878
        master observer cannot be stopped
        
        
        Cause
        The master observer cannot be stopped when another observer is registered.
        Action
        Use the SET MASTEROBSERVER command to establish another observer as the master observer. Then use the STOP OBSERVER command to stop the former master observer.