[midPoint] Can't import LDAP groups, user reconciliation ends with errors (3.4.1)

[Wojciech Staszewski]

Hello,

Something bad happened to my LDAP resource.
It worked well, I imported all users, some groups, configured synchronization and all task was processed ok.
But two days ago I saw errors in reconciliation:

"Last error when processing object	SystemException: java.lang.NullPointerException"

O the resource -> Accounts -> Result:
Failed to reconciliation: java.lang.IllegalStateException: Subresult com.evolveum.midpoint.model.impl.lens.projector.InboundProcessor.processInbound of operation com.evolveum.midpoint.model.impl.lens.projector.Projector.project is still UNKNOWN during cleanup; during handling of exception java.lang.NullPointerException

Since yesterday I'm trying to import other groups from this resource, but every time i got this error:

"No name in new object null as produced by template null in iteration 0, we cannot process an object without a name"
And the role in Midpoint is created with empty name.

And in error details:

com.evolveum.midpoint.util.exception.NoFocusNameSchemaException: No name in new object null as produced by template null in iteration 0, we cannot process an object without a name

Execute (Model) 
Schema violation during processing shadow: shadow: cn=Accounting Managers,ou=Groups,dc=xxx,dc=xx (OID:8c0692d3-3235-4b9d-bd89-da1bc80b3f31): Schema violation: Invalid attribute: org.identityconnectors.framework.common.exceptions.InvalidAttributeValueException(Error modifying LDAP entry cn=Accounting Managers,ou=Groups,dc=xxx,dc=xx: [remove:uniqueMember: cn=Directory Manager,remove:cn: Accounting Managers,]: objectClassViolation: missing attribute "cn" required by object class "groupOfUniqueNames"? (65))

Ldapsearch on my 389ds shows "cn" attribute in the groups:

# Accounting Managers, Groups, xxx.xx
dn: cn=Accounting Managers,ou=Groups,dc=xxx,dc=xx
objectClass: top
objectClass: groupOfUniqueNames
cn: Accounting Managers
ou: groups
description: People who can manage accounting entries
uniqueMember: cn=Directory Manager

# search result
search: 2
result: 0 Success

# numResponses: 2
# numEntries: 1

Actually I don't know where to find a reason, I reviewed schema, schema handling and synchronization both users and groups, compared them with Evolveum example 389ds resource and see no differences. Any help appreciated.
Wociech Staszewski