Primary database error ORA-07217: sltln: environment variable cannot be evaluated

Error:

Primary database throw below error while trying to transport archive log to standby database

ALTER SYSTEM SET log_archive_dest_state_2='enable' SCOPE=BOTH;
Errors in file /oracle/diag/rdbms/<oracle_sid>/trace/<oracle_sid>arc2_2894.trc:
ORA-07217: sltln: environment variable cannot be evaluated.
ARC2: FAL archive failed with error 7217. See trace for details
Errors in file /oracle/diag/rdbms/mdmprd/mdmprd/trace/<oracle_sid>_arc2_2894.trc:
ORA-16055: FAL request rejected
ARCH: FAL archive failed. Archiver continuing

Fix:

$ORACLE_SID needs to be replaced by proper value

Modify log_archive_format to correct value and restart the redo transport.