无法访问本页的原因是:

Exception of type 'System.Web.HttpException' was thrown.
System.Web.HttpException (0x80004005): Exception of type 'System.Web.HttpException' was thrown. ---> System.Web.HttpException (0x80004005): A potentially dangerous Request.Path value was detected from the client (?). at System.Web.HttpRequest.ValidateInputIfRequiredByConfig() at System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context)