Data Guard errors and solution- i faced

today i started the primary and standby database, i got this error message in primary database
ORA-16649: database will open after Data Guard broker has evaluated Fast-Start Failover status

after connecting with the observer, i gave show configuration verbose command and show database verbose 'whiteowl' command, it showed the below error message.
note: here my database name whiteowl

ORA-16820:

Fast-Start Failover observer is no longer observing this database

Cause:	A previously started observer was no longer actively observing this database. A significant amount of time elapsed since this database last heard from the observer. Possible reasons were: - The node where the observer was running was not available. - The network connection between the observer and this database was not available. - Observer process was terminated unexpectedly.
Action:	Check the reason why the observer cannot contact this database. If the problem cannot be corrected, stop the current observer by connecting to the Data Guard configuration and issue the DGMGRL "STOP OBSERVER" command. Then restart the observer on another node. You may use the DGMGRL "START OBSERVER" command to start the observer on the other node.

what i have done?

i checked the listeners, tnsnames.ora files and tnsping command in primary,standby, observer machines
and then as above mentioned i stop the observer and then start the observer from primary database machine.
now its working fine.
DGMGRL> show configuration verbose;

Configuration
  Name:                whiteowl
  Enabled:             YES
  Protection Mode:     MaxAvailability
  Fast-Start Failover: ENABLED
  Databases:
    whiteowl - Primary database
    blackowl - Physical standby database
             - Fast-Start Failover target

Fast-Start Failover
  Threshold: 30 seconds
  Observer:  rac1

Current status for "whiteowl":
SUCCESS

DGMGRL>

reference:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14230/sofo.htm#BCGHBJJI