Hello, I am seeing many error entries on opac-error.log. Sat Jun 19 18:15:47.054074 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in hash element at /usr/share/koha/lib/C4/XSLT.pm line 359.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.054370 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in scalar assignment at /usr/share/koha/lib/C4/Koha.pm line 550.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.076539 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in hash element at /usr/share/koha/lib/C4/XSLT.pm line 359.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.076831 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in scalar assignment at /usr/share/koha/lib/C4/Koha.pm line 550.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.099125 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in hash element at /usr/share/koha/lib/C4/XSLT.pm line 359.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.099419 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in scalar assignment at /usr/share/koha/lib/C4/Koha.pm line 550.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.121645 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in hash element at /usr/share/koha/lib/C4/XSLT.pm line 359.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl [Sat Jun 19 18:15:47.121938 2021] [cgi:error] [pid 14502] [client 185.191.171.33:63720] AH01215: [Sat Jun 19 18:15:47 2021] opac-search.pl: Use of uninitialized value in scalar assignment at /usr/share/koha/lib/C4/Koha.pm line 550.: /usr/share/koha/opac/cgi-bin/opac/ opac-search.pl I checked client ip address. Non-authoritative answer: 33.171.191.185.in-addr.arpa name = crawl27.bl.semrush.com. Any ideas what the errors mean. Do you know what this client is trying to do with my koha system? How do I fix the errors? On another log - intranet-error.log. I saw the error entry below. What does that mean? How do I fix the issue? FYI. I am running Koha version 20.11.03 and Elasticsearch version 6.8.9. Sat Jun 19 18:14:39.867657 2021] [cgi:error] [pid 14436] [client xxx.xxx.xxx.xxx:59533] AH01215: [Sat Jun 19 18:14:39 2021] addbiblio.pl: [Request] ** [http://localhost:9200]-[400] [illegal_argument_exception] Fielddata is disabled on text fields by default. Set fielddata=true on [local-number__sort] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead., called from sub Search::Elasticsearch::Role::Client::Direct::__ANON__ at /usr/share/koha/lib/Koha/SearchEngine/Elasticsearch/Search.pm line 96. With vars: {'body' => {'status' => 400,'error' => {'grouped' => bless( do{\\(my $o = 1)}, 'JSON::PP::Boolean' ),'caused_by' => {'reason' => 'Fielddata is disabled on text fields by default. Set fielddata=true on [local-number__sort] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.','caused_by' => {'type' => 'illegal_argument_exception','reason' => 'Fielddata is disabled on text fields by default. Set fielddata=true on [local-number__sort] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.'},'type' => 'illegal_argument_exception'},'reason' => 'all shards failed','root_cause' => [{'reason' => 'Fielddata is disabled on text fields by default. Set fielddata=true on [local-number__sort] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.','type' => 'illegal_argument_exception'}],'phase' => 'query','failed_shards' => [{'node' => 'XixKhqGwRtinFdkt7uwTWw','index' => 'koha_lib_authorities','shard' => 0,'reason' => {'type' => 'illegal_argument_exception','reason' => 'Fielddata is disabled on text fields by default. Set fielddata=true on [local-number__sort] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.'}}],'type' => 'search_phase_execution_exception'}},'request' => {'ignore' => [],'body' => {'size' => 20,'sort' => [{'local-number__sort' => 'asc'}],'query' => {'bool' => {'filter' => {'term' => {'authtype.raw' => 'PERSO_NAME'}},'must' => [{'term' => {'match-heading.ci_raw' => 'Schmidt Thomas E'}}]}},'from' => 0},'path' => '/koha_lib_authorities/_search','mime_type' => 'application/json','qs' => {},'serialize' => 'std','method' => 'GET'},'status_code' => 400}: /usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer: http://xxx.xxx.org:8080/cgi-bin/koha/cataloguing/addbiblio.pl?biblionumber=1... Best Regards, Chee