oracle 11.2.0.3 shutdown immediate

Completed: ALTER DATABASE DISMOUNT
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
ARCH: Archival disabled due to shutdown: 1089
Thu Dec 10 22:34:11 2020
Errors in file /oracle/app/oracle/diag/rdbms/zwa/zwa1/trace/zwa1_smon_18859.trc:
ORA-21779: duration not active
Shutting down archive processes
Archiving is disabled
Thu Dec 10 22:34:11 2020
Stopping background process VKTM
SMON (ospid: 18859): terminating the instance due to error 21779
Thu Dec 10 22:34:11 2020
System state dump requested by (instance=1, osid=18859 (SMON)), summary=[abnormal instance termination].
System State dumped to trace file /oracle/app/oracle/diag/rdbms/zwa/zwa1/trace/zwa1_diag_18115.trc
Instance terminated by SMON, pid = 18859