500 Internal Server Error，纠结无解么！求助！！！

M享主机-M2-S(云)   就网站首页报错。其他子页还没有问题。

.htaccess文件没有。
文件权限的话  我自己在ftp中右键给文件夹755，文件644了。
都不好用啊
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Internal Server Error


The server encountered an internal error ormisconfiguration and was unable to completeyour request.
Please contact the server administrator, webmaster@zhan99.com and inform them of the time the error occurred,and anything you might have done that may havecaused the error.
More information about this error may be availablein the server error log.】