Error message

• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::XML(): Empty string supplied as input in RepositoryQuery::parseSparqlResults() (line 40 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).
• Warning: XMLReader::read(): Load Data before trying to read in RepositoryQuery::parseSparqlResults() (line 45 of /var/www/drupal/sites/all/libraries/tuque/RepositoryQuery.php).