Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in /opt/lampp/htdocs/openbiblio/classes/Query.php on line 223

Internal Error - You've Probably Found a Bug

Please give all the information on this page to your support personnel.

Tried to make database query before connection.
Debug Backtrace (most recent call first):

/opt/lampp/htdocs/openbiblio/classes/Error.php:91 FatalHandler->printBackTrace()
/opt/lampp/htdocs/openbiblio/classes/Error.php:59 FatalHandler->internalError('Tried to make database query before connection.')
/opt/lampp/htdocs/openbiblio/classes/Query.php:87 Fatal->internalError('Tried to make database query before connection.')
/opt/lampp/htdocs/openbiblio/classes/Query.php:286 Query->_act('select count(*) as rowcount from biblio left join biblio_copy on biblio.bibid=biblio_copy.bibid left join biblio_field on biblio_field.bibid=biblio.bibid and biblio_field.tag=\'242\' and biblio_field.subfield_cd=\'a\' where ((`biblio`.`title` like \'\'  or `biblio`.`title_remainder` like \'\'  or `biblio_field`.`field_data` like \'\'  or `biblio`.`author` like \'\'  or `biblio`.`responsibility_stmt` like \'\'  or `biblio`.`topic1` like \'\'  or `biblio`.`topic2` like \'\'  or `biblio`.`topic3` like \'\'  or `biblio`.`topic4` like \'\'  or `biblio`.`topic5` like \'\' ))  and  (biblio.collection_cd=2 or biblio.collection_cd=7) and  (biblio.material_cd=2)')
/opt/lampp/htdocs/openbiblio/classes/BiblioSearchQuery.php:141 Query->_query('select count(*) as rowcount from biblio left join biblio_copy on biblio.bibid=biblio_copy.bibid left join biblio_field on biblio_field.bibid=biblio.bibid and biblio_field.tag=\'242\' and biblio_field.subfield_cd=\'a\' where ((`biblio`.`title` like \'\'  or `biblio`.`title_remainder` like \'\'  or `biblio_field`.`field_data` like \'\'  or `biblio`.`author` like \'\'  or `biblio`.`responsibility_stmt` like \'\'  or `biblio`.`topic1` like \'\'  or `biblio`.`topic2` like \'\'  or `biblio`.`topic3` like \'\'  or `biblio`.`topic4` like \'\'  or `biblio`.`topic5` like \'\' ))  and  (biblio.collection_cd=2 or biblio.collection_cd=7) and  (biblio.material_cd=2)', 'Errore nel conteggio dei risultati della ricerca.')
/opt/lampp/htdocs/openbiblio/shared/biblio_search.php:174 BiblioSearchQuery->search('6', array (
  0 => '',
), 1, 'title', 'and', array (
  0 => '2',
  1 => '7',
), array (
  0 => '2',
), false)

Any Hint?