makocan回答ポイント 70ptウォッチ

PHPでセッションを扱う際に下記のエラーが出てきます。

原因は分かりますでしょうか？
ちなみに下記のline53ではsession_start()を実行しています。

Warning: session_start() [function.session-start]: open( This option enables administrators to make their users invulnerable to ; attacks which involve passing session ids in URLs; defaults to 0. ; session.use_only_cookies = 1 ; Name of the session (used as cookie name). session.name = PHPSESSID ; Initialize session on request startup. session.auto_start = 0 ; Lifetime in seconds of cookie or, if 0, until browser is restarted. session.cookie_lifetime = 0 ; The path for which the cookie is valid. session.cookie_path = / ; The domain for which the cookie is valid. session.cookie_domain = ; Handler used to serialize data. php is the standard serializer of PHP. session.serialize_handler = php ; Define the probability that the 'garbage collection' process is started ; on every session initialization. ; The probability is calculated by using gc_probability/gc_divisor, ; e.g. 1/100 means there is a 1% chance that the GC process starts ; on each request. session.gc_probability = 1 in /home/rimnet-home/yokuataru/lib/mail.php on line 53