很多程序员在CI中使用session的时候，开启自动加载session之后网站就报错了，具体错误信息如下：In order to use the Session class you are required to set an encryption key
下面一起来看问题解决办法。
提示信息说明：
如果想用session类的话就必须要设置一个加密的密钥
！那就给设置一个吧，毕竟也是出于安全考虑。打开application/config/config.PHP找到Encryption Key
代码如下:
/*
|--------------------------------------------------------------------------
| Encryption Key
|--------------------------------------------------------------------------| If you use the Encryption class or the Session class you
| MUST set an encryption key. See the user guide for info.*/
$config['encryption_key'] = 'xxxxx';//在这里加上密钥即可正常！
|--------------------------------------------------------------------------
| Encryption Key
|--------------------------------------------------------------------------| If you use the Encryption class or the Session class you
| MUST set an encryption key. See the user guide for info.*/
$config['encryption_key'] = 'xxxxx';//在这里加上密钥即可正常！
