Could not validate ASMSNMP Password due to following error – “ORA-1031: insufficient privileges”
Cause:
This error happens when configuring OEM in database installation
The error occur due to missing ASMSNMP user which is used for monitoring ASM health from OEM

Check if user exist
[oracle@exdbadm01 bin]$ . oraenv
ORACLE_SID = [+ASM] ?
The Oracle base remains unchanged with value /apps01/base
[oracle@exdbadm01 bin]$ sqlplus / as sysasm
SQL*Plus: Release 11.2.0.4.0 Production on Tue Jan 26 12:38:25 2021
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Automatic Storage Management option
SQL> alter user asmsnmp identified by password;
alter user asmsnmp identified by password
*
ERROR at line 1:
ORA-01918: user 'ASMSNMP' does not exist
Workaround:
Create the user
SQL> create user ASMSNMP identified by password;
create user ASMSNMP identified by password
*
ERROR at line 1:
ORA-01990: error opening password file
'/apps01/base/product/11.2.0/grid/dbs/orapw'
Check if password file exist
If password file exist,then ignore this step
[oracle@exdbadm01 bin]$ cd /apps01/base/product/11.2.0/grid/dbs/
[oracle@exdbadm01 dbs]$ ls -lrt *orapw*
ls: *orapw*: No such file or directory
Create a password file
[oracle@exdbadm01 dbs]$ orapwd file=orapw entries=30
Enter password for SYS:
Create the user now
[oracle@exdbadm01 dbs]$ sqlplus / as sysasm
SQL> create user ASMSNMP identified by password;
User created.
SQL> grant sysdba,sysoper to asmsnmp;
Grant succeeded.
Give the password of ASMSNMP ,when prompt during installation

You should not see the warning now in installation window