switchover failed with ORA-16775: target standby database in broker operation has potential data loss

Problem Description

I switchover from primary to standby successfully but when I swithback to primary I got following error:

DGMGRL> show configuration
Configuration
  Name:                DBAPRD.intdata.com
  Enabled:             YES
  Protection Mode:     MaxPerformance
  Databases:
    DBALC  - Primary database
    DBAPRD - Physical standby database
    DBADR  - Physical standby database

Fast-Start Failover: DISABLED

Current status for "DBAPRD.intdata.com":
SUCCESS

DGMGRL> switchover to 'DBAPRD'
DGMGRL> Performing switchover NOW, please wait...
Error: ORA-16775: target standby database in broker operation has potential data loss

Failed.
Unable to switchover, primary database is still "DBALC"

DGMGRL> show configuration
Configuration
  Name:                DBAPRD.intdata.com
  Enabled:             YES
  Protection Mode:     MaxPerformance
  Databases:
    DBALC  - Primary database
    DBAPRD - Physical standby database
    DBADBDR  - Physical standby database

Fast-Start Failover: DISABLED

Current status for "DBAPRD.intdata.com":
Warning: ORA-16607: one or more databases have failed

Following error was found in alertlog of primary database:

Errors in file /u02/oracle/diag/dbaPRD/diag/rdbms/dbalc/dbaLC/trace/dbaLC_lns1_21171.trc:
ORA-03135: connection lost contact
LGWR: Error 3135 closing archivelog file '(DESCRIPTION=(ADDRESS_LIST = (ADDRESS=(PROTOCOL=tcp)(HOST=racprod1-v)(PORT=1540)))(CONNECT_DATA=(SERVICE_NAME=dbaPRD.intdata.com)(SERVER=DEDICATED)))'
Sat Jun 08 19:20:51 2013
Deleted Oracle managed file +dba_FLASH/dbalc/archivelog/2013_04_14/thread_1_seq_130382.8527.812711313
Waiting for all non-current ORLs to be archived...
Waiting for the ORL for thread 1 sequence 136062 to be archived...
Sat Jun 08 19:20:59 2013
ARC3: Archiving not possible: failed standby destinations
ARCH: Archival stopped, error occurred. Will continue retrying
ORACLE Instance dbaLC - Archival Error
ORA-16014: log 2 sequence# 136062 not archived, no available destinations
ORA-00312: online log 2 thread 1: '+dba_DATA/dbalc/onlinelog/group_2.311.794395241'
ORA-00312: online log 2 thread 1: '+dba_FLASH/dbalc/onlinelog/group_2.303.794395255'
Errors in file /u02/oracle/diag/dbaPRD/diag/rdbms/dbalc/dbaLC/trace/dbaLC_arc3_14518.trc:
ORA-16014: log 2 sequence# 136062 not archived, no available destinations
ORA-00312: online log 2 thread 1: '+dba_DATA/dbalc/onlinelog/group_2.311.794395241'
ORA-00312: online log 2 thread 1: '+dba_FLASH/dbalc/onlinelog/group_2.303.794395255'
......
ORA-16416 signalled during: ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN...

Cause:  

The target standby database in the broker operation did not have all the redo logs from the primary database.


Solution:
I tried "alter system swith logfile" but it didnt' work.
Restart primary database solve the problem.

Conclusion
Before swithover , run a few log switchover to make sure log can ship to standby.