A fix is in HEAD. delta-syncrepl will now fallback to regular refresh in additional cases - LDAP_ALREADY_EXISTS, which may occur for old Adds, LDAP_NO_SUCH_OBJECT, for cases already covered in ITS#5376, LDAP_NO_SUCH_ATTRIBUTE, for old Modifies, and LDAP_TYPE_OR_VALUE_EXISTS also for old Modifies. Pretty sure that covers all of the possible out-of-sync cases. Please test.