Warning: ORA-16809: multiple warnings detected for the database

 In DGMGRL Configuration you might see this error 

Connect to DGMGRL and check the configuration 

Host[DB]_OSUSER> dgmgrl

DGMGRL for Linux: Version 12.1.0.2.0 - 64bit Production

Copyright (c) 2000, 2013, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.

DGMGRL> connect sys/******@<DB_UNIQUE_NAME>

Connected as SYSDBA.

DGMGRL> show configuration;

Configuration - <dbname>_dg_config

  Protection Mode: MaxPerformance

  Members:

  <db_unique_name> - Primary database

    <db_unique_name> - Physical standby database

      Warning: ORA-16809: multiple warnings detected for the database

Fast-Start Failover: DISABLED

Configuration Status:

WARNING   (status updated 22 seconds ago)

Validate Database against primary and standby 

++++++++++++++++++++++++++++++++++++

DGMGRL> validate database <db_unique_name>;

  Database Role:    Primary database

  Ready for Switchover:  Yes

  Flashback Database Status:

    <db_unique_name>:  Off

DGMGRL> validate database <db_unique_name>;

  Database Role:     Physical standby database

  Primary Database:  <db_unique_name>

  Ready for Switchover:  No

  Ready for Failover:    Yes (Primary Running)

  Flashback Database Status:

    <db_unique_name>:  Off

    <db_unique_name>:  Off

  Standby Apply-Related Information:

    Apply State:      Running

    Apply Lag:        48 minutes 48 seconds (computed 44 seconds ago)

    Apply Delay:      0 minutes

  Log Files Cleared:

    <db_unique_name> Standby Redo Log Files:  Cleared

    <db_unique_name> Online Redo Log Files:   Cleared

    <db_unique_name> Standby Redo Log Files:  Not Available

  Current Log File Groups Configuration:

    Thread #  Online Redo Log Groups  Standby Redo Log Groups Status

              (<db_unique_name>)           (<db_unique_name>)

    1         3                       0                       Insufficient SRLs

    Warning: standby redo logs not configured for thread 1 on <db_unique_name>

    2         3                       0                       Insufficient SRLs

    Warning: standby redo logs not configured for thread 2 on <db_unique_name>

Solution : 

Add Redolog groups for standby redolog files 

+++++++++++++++++++++++++++++++++++++

ALTER DATABASE ADD STANDBY LOGFILE THREAD 1 

      group 7 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 8 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 9 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 10 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE;

ALTER DATABASE ADD STANDBY LOGFILE THREAD 2 

      group 11 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 12 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 13 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE,

      group 14 ('+DATAC1','+RECOC1') SIZE 4 G  REUSE;

crosscheck again you will see its in sync if not try to restart MRP process