ok now,
May be this is hapening because of internal error occured in your project....
In my website(not DNN), what i did is I wrote a application_error event, which will fire, if any where in the project error occurs and write to a log file, and here is the code below, try to handel the error....(not sure about the code will be same in DNN or not, just check once)
void Application_Error(object sender, EventArgs e)
{
// Code that runs when an unhandled error occurs
try
{
//if (Server.GetLastError().GetType() == typeof(HttpException))
//{
if (!Server.GetLastError().Message.Trim().Contains("File does not exist."))
{
Session["UserID"] = null;
Session.Abandon();
Session.Clear();
Response.Expires = 0;
Response.Cache.SetNoStore();
Response.AppendHeader("Pragma", "no-cache");
Response.Clear();
HttpApplication app = (HttpApplication)sender;
HttpContext context = app.Context;
Exception ex = context.Server.GetLastError().GetBaseException();
context.Response.Clear();
ExceptionUtility.LogException(ex, "Global.asax", "Application_Error");
}
//}
}
catch (Exception ex)
{
string strErro = ex.Message;
}
}