ORA-16647: could not start more than one observer

1. Error while starting the fsfo observer in new node.

[W000 07/20 22:41:58.95] Failed to start the Observer.
Error: ORA-16647: could not start more than one observer

2.Stop the observer and start the observer in the new node

DGMGRL> show fast_start failover

Fast-Start Failover: ENABLED

  Threshold:          30 seconds
  Target:             orcl_uk
  Observer:           ol6-112-rac1.localdomain
  Lag Limit:          20 seconds
  Shutdown Primary:   TRUE
  Auto-reinstate:     TRUE
  Observer Reconnect: (none)
  Observer Override:  FALSE

Configurable Failover Conditions
  Health Conditions:
    Corrupted Controlfile          YES
    Corrupted Dictionary           YES
    Inaccessible Logfile            NO
    Stuck Archiver                  NO
    Datafile Offline               YES

  Oracle Error Conditions:
    (none)

DGMGRL> stop observer
Done.
DGMGRL> show fast_start failover

Fast-Start Failover: ENABLED

  Threshold:          30 seconds
  Target:             orcl_uk
  Observer:           (none)
  Lag Limit:          20 seconds
  Shutdown Primary:   TRUE
  Auto-reinstate:     TRUE
  Observer Reconnect: (none)
  Observer Override:  FALSE

Configurable Failover Conditions
  Health Conditions:
    Corrupted Controlfile          YES
    Corrupted Dictionary           YES
    Inaccessible Logfile            NO
    Stuck Archiver                  NO
    Datafile Offline               YES

  Oracle Error Conditions:
    (none)

3.Start the observer process

]$ dgmgrl -logfile '/u03/app/oracle/diag/rdbms/orcl_uk/orcl2/trace/observer.log'  'sys/sys123@orcl_uk' 'start observer' &
[1] 12870
[oracle@ol6-112-rac2 trace]$ DGMGRL for Linux: Version 12.1.0.1.0 - 64bit Production

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