版主救急，我网站会员登陆不上，老提示服务器内部错误，麻烦帮我看看

状况发生在今天上午，我的空间是用的康盛的5G的虚拟空间。
表现如下：
1、网站忽然变得很不稳定，一会就打不开了，联系主机客服，说是服务器有故障，重新启动
2、重新启动后网站很不稳定，网站老提示内部错误，如下：
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
，现在静态页面可以访问，但是登陆不进去，网站发生问题之前没有退出的会员还能断断续续的操作下。我刚刚注册了下，居然提示用户名已经存在，但是明明之前没有那个用户名的。

现在我站点依然不能正常访问，我都把原始文件全部覆盖回去了，但是问题依然。麻烦版主大人帮我看看，非常感谢！非常感谢！我都弄了一天了。

网址：http://www.yqwb.net测试帐号：魅魅 111111

版主麻烦帮我看看好吗

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

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