[Samba] SAMBA 4.20 - function level upgrade

[Tomáš Havlín]

Hello Samba Dancers,
I tried to do function level upgrade on my testing instalation of samba.
Finished upgrade from 4.18 to 4.20. I put ad dc functional level = 2016 
line to smb.conf, restarted samba. But command samba-tool domain 
schemaupgrade --schema=2019 ends with error.

Could I ask you check my progress or find solution?

samba-tool domain schemaupgrade --schema=2019
Temporarily overriding 'dsdb:schema update allowed' setting
Applying Sch70.ldf updates...
Unable to find attribute msDS-DeviceMDMStatus in the schema
5 changes applied
Applying Sch71.ldf updates...
7 changes applied
Applying Sch72.ldf updates...
5 changes applied
Applying Sch73.ldf updates...
5 changes applied
Applying Sch74.ldf updates...
../../source4/dsdb/schema/schema_init.c:816: name == NULL in 
CN=ms-DS-Key-Credential,CN=Schema,CN=Configuration,DC=raisa,DC=intra
dsdb_schema_set_el_from_ldb_msg_dups() WERR_INVALID_PARAMETER
Exception: (1, 'operations error at 
../../source4/dsdb/samdb/ldb_modules/resolve_oids.c:674')
Encountered while trying to apply the following LDIF
----------------------------------------------------
dn: CN=ms-DS-Key-Credential,CN=Schema,CN=Configuration,DC=raisa,DC=intra
changetype: add
objectClass: classSchema
ldapDisplayName: msDS-KeyCredential
adminDisplayName: msDS-KeyCredential
adminDescription: An instance of this class contains key material.
governsId: 1.2.840.113556.1.5.297
objectClassCategory: 1
rdnAttId: cn
schemaIdGuid:: Q1Uf7i58akeLP+EfSvbEmA==
defaultSecurityDescriptor: 
D:(A;;RPWPCRCCDCLCLOLORCWOWDSDDTDTSW;;;EA)(A;;RPWPCRCCDCLCLORCWOWDSDDTSW;;;SY)
defaultHidingValue: FALSE
showInAdvancedViewOnly: TRUE
systemOnly: FALSE
systemFlags: 16
instanceType: 4
subClassOf: top
systemPossSuperiors: container
systemMustContain: 1.2.840.113556.1.4.2315
systemMayContain: msDS-KeyMaterial
systemMayContain: msDS-KeyUsage
systemMayContain: msDS-KeyPrincipal
systemMayContain: msDS-DeviceDN
systemMayContain: msDS-ComputerSID
systemMayContain: msDS-CustomKeyInformation
systemMayContain: msDS-KeyApproximateLastLogonTimeStamp

Exception: (1, 'operations error at 
../../source4/dsdb/samdb/ldb_modules/resolve_oids.c:674')
Error encountered, aborting schema upgrade
ERROR: Failed to upgrade schema




regards
THAV