The session id is too long or contains illegal characters, valid characters are a-z, A-Z, 0-9 and '-,'

have a look at this session_start() discussion for a work-around:

session_start() generate a warning if PHPSESSID contains illegal characters

Warning: session_start() [function.session-start]: The session id contains illegal characters, valid characters are a-z, A-Z, 0-9 and '-,' in /home/para/dev/mon_site/header.php on line 17

To avoid i wrote this :

   <?php
        function my_session_start()
        {
            if (ini_get('session.use_cookies') && isset($_COOKIE['PHPSESSID'])) {
                $sessid = $_COOKIE['PHPSESSID'];
            } elseif (!ini_get('session.use_only_cookies') && isset($_GET['PHPSESSID'])) {
                $sessid = $_GET['PHPSESSID'];
            } else {
                session_start();
                return false;
            }

           if (!preg_match('/^[a-z0-9]{32}$/', $sessid)) {
                return false;
            }
            session_start();

           return true;
        }
    ?>

You might be using Mink or Behat. Please, make sure that they are loaded only for their environment and not dev/prod. See:

https://github.com/symfony/symfony/issues/1766

By adding our .cleanup() method to the String object itself, you can then cleanup any string in Javascript simply by calling a local method, like this:

# Attaching our method to the String Object
String.prototype.cleanup = function() {
   return this.toLowerCase().replace(/[^a-zA-Z0-9]+/g, "-");
}

# Using our new .cleanup() method
var clean = "Hello World".cleanup(); // "hello-world"

Because there is a plus sign at the end of the regular expression it matches one or more characters. Thus, the output will always have one '-' for each series of one or more non-alphanumeric characters:

# An example to demonstrate the effect of the plus sign in the regular expression above
var foo = "  Hello   World    . . .     ".cleanup(); // "-hello-world-"

Without the plus sign the result would be "--hello-world--------------" for the last example.