Hello, It was the system preference ( UseQueryParse )that stopped intranet staff client catalog search when we stopped it the search has been worked correctly. But stopping this system preference affected on adding new catalog records negatively specially Arabic records, Always the message of (duplicated record) appears. Here's the reason: the reason is because (isbn) number in many Arabic records is not necessary in old records i mean it has the value (NULL) in koha DB and when checking isbn numbers it considers the NULL values are for the same record, so it always asking if that record is identical to another one in database or not if we entered the record without (isbn) number, so i think the following snippet of code in (search.pm -->koha v3.16.01) doesn't exclude NULL values when checking record duplication # search duplicate on ISBN, easy and fast.. # ... normalize first if ( $result->{isbn} ) { $result->{isbn} =~ s/\(.*$//; $result->{isbn} =~ s/\s+$//; $query = "isbn:$result->{isbn}"; } I'm asking if that is a bug??? thanks