Error: Missing schema location in RootDSE while setting up OpenLdap server - openldap

Question

I have done setup of OpenLdap 2.6.3 on CentOS8. I followed all the steps and I am trying to connect in Apache Directory Studio. It throws the error "Error while opening connection
-Missing schema location in RootDSE, using default schema". Please could you help me in this.
The input given in RootDN is:
dn: cn=config
objectClass: olcGlobal
cn: config
olcArgsFile: /var/lib/openldap/slapd.args
olcPidFile: /var/lib/openldap/slapd.pid
dn: cn=schema,cn=config
objectClass: olcSchemaConfig
cn: schema
dn: cn=module,cn=config
objectClass: olcModuleList
cn: module
olcModulepath: /usr/libexec/openldap
olcModuleload: back_mdb.la
# Include more schemas in addition to default core
include: file:///etc/openldap/schema/core.ldif
include: file:///etc/openldap/schema/cosine.ldif
include: file:///etc/openldap/schema/nis.ldif
include: file:///etc/openldap/schema/inetorgperson.ldif
include: file:///etc/openldap/schema/sudo.ldif
dn: olcDatabase=frontend,cn=config
objectClass: olcDatabaseConfig
objectClass: olcFrontendConfig
olcDatabase: frontend
olcAccess: to dn.base="cn=Subschema" by * read
olcAccess: to *
by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" manage
by * none
dn: olcDatabase=config,cn=config
objectClass: olcDatabaseConfig
olcDatabase: config
olcRootDN: cn=config
olcAccess: to *
by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" manage
by * none
and the input given in binddnuser.ldif:
dn: ou=system,dc=ldapmaster,dc=connectors,dc=com
objectClass: organizationalUnit
objectClass: top
ou: system
dn: cn=readonly,ou=system,dc=ldapmaster,dc=connectors,dc=com
objectClass: organizationalRole
objectClass: simpleSecurityObject
cn: readonly
userPassword: {SSHA}p8Ivp9Qc3YQr1hO3DHuX2GMvTGAbdBux
description: Bind DN user for LDAP Operations