OpenLDAP failing to start slapd service

I tried to install openldap by following this guide: https://computingforgeeks.com/install-configure-openldap-server-centos/

but the service does not start showing the following error:
slapd.service - OpenLDAP Server Daemon
Loaded: loaded (/etc/systemd/system/slapd.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2022-11-18 23:19:23 CET; 1min 20s ago
Docs: man:slapd
man:slapd-mdb
Process: 7611 ExecStart=/usr/libexec/slapd -u ldap -g ldap -h ${SLAPD_URLS} $SLAPD_OPTIONS (code=exited, status=1/FAILURE)

Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: ldif_read_file: checksum error on "/etc/openldap/slapd.d/cn=config.ldif"
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: ldif_read_file: checksum error on "/etc/openldap/slapd.d/cn=config/olcDatabase={1}mdb.ldif"
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: ldif_read_file: checksum error on "/etc/openldap/slapd.d/cn=config/olcDatabase={2}mdb.ldif"
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: olcSuffix: value #0: namingContext "dc=ldapmaster,dc=company,dc=it" already served by a preceding mdb database serving namingContext "dc=ldapmaster,dc=company,dc=it"
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: config error processing olcDatabase={2}mdb,cn=config: namingContext "dc=ldapmaster,dc=company,dc=it" already served by a preceding mdb database
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: slapd stopped.
Nov 18 23:19:23 itl-cslapp-54 slapd[7611]: connections_destroy: nothing to destroy.
Nov 18 23:19:23 itl-cslapp-54 systemd[1]: slapd.service: Control process exited, code=exited status=1
Nov 18 23:19:23 itl-cslapp-54 systemd[1]: slapd.service: Failed with result 'exit-code'

how can i fix it?

Thanks