Fatal error: Uncaught mysqli_sql_exception: Prepared statement needs to be re-prepared in /var/www/html/eng_mysqli.php:84 Stack trace: #0 /var/www/html/eng_mysqli.php(84): mysqli_stmt->execute() #1 /var/www/html/publications/thesis.php(27): PW_sql2rsPS() #2 {main} thrown in /var/www/html/eng_mysqli.php on line 84