Elmah is not logging NullReference exception

Question

Good afternoon,

in my project is installed elmah framework to logging exceptions. On the localhost it works fine, but when I deploy it to production it stops logging null reference exceptions. All others exceptions are logged (or I didn't find out next which is not logged). I have set logging into SqlServer.

I can't find out what is wrong, can someone give me advice please? (How I said it loggs all exceptions what I fired but only this one is never caught)

Thank you

Answer 1

Well, Thomas Ardal answered right.

Problem was in the FilterConfig.cs file. Because in default settings it didn't want log any 500 errors, dangerous requests, null reference exceptions etc, i have added this lines:

public class ElmahHandleErrorAttribute : HandleErrorAttribute
{
    public override void OnException(ExceptionContext filterContext)
    {
        if(filterContext.Exception is HttpRequestValidationException)
        {
            ErrorLog.GetDefault(HttpContext.Current).Log(new Error(filterContext.Exception));
        }
    }
}

and added this line to the RegisterGlobalFilters method on the first place.

filters.Add(new ElmahHandleErrorAttribute());

After that it started log some exceptions but not all. Solution is that I remove if condition and catch everything. So if anyone will have similar problem, be sure, that problem will be somewhere in filters...