error adding members to group

[Hannu Tikka]

For a while I haven't been able to add members to groups.
Using command: ldbmodify or net group addmembers
gives following error:

ERROR: Failed to add members "xxxxx" to group "yyyyy": objectclass_attrs:
attribute 'parentGUID' on entry 'CN=yyyyy,OU=xxxxx,CN=xxxx,DC=xx,DC=xx'
does not exist in the specified objectclasses!

Is my ldb database somehow broken?

using ldbsearch finds attribute parentGUID for the group object.