Erro ao conectar com o Base de Dados!

PDOException: SQLSTATE[HY000] [1040] Too many connections in /home/apliccursos/public_html/sistema/conexao.php:9 Stack trace: #0 /home/apliccursos/public_html/sistema/conexao.php(9): PDO->__construct('mysql:dbname=ap...', 'apliccursos_prk...', 'd4Y}D9PY1PU?') #1 /home/apliccursos/public_html/curso.php(2): require_once('/home/apliccurs...') #2 {main}