A web app I’m working on which uses web service calls a lot is using Elmah for error logging.

Unfortunately web service calls consistently result in the useless ‘Server was unable to process request.’ message.

Originally I thought I could patch Elmah to log session variables then log the detail in the session in a Global.asax application_error handler.  Unfortunately, the Elmah error handler appears to consistently run before the application_error handler, so that doesn’t work (although it’s still nice to have session variables logged).

So I did some quick hacking on Elmah to get it to pull out the useful SoapException.Detail message. 

In Elmah’s Error.cs file, after:

if (httpException != null)
{
    _statusCode = httpException.GetHttpCode();
    _webHostHtmlMessage = Mask.NullString(httpException.GetHtmlErrorMessage());
}

I added:

// If this is a SOAP exception, then replace the message information with more useful info
System.Web.Services.Protocols.SoapException soapException = baseException as System.Web.Services.Protocols.SoapException;
if (soapException != null && soapException.Detail != null)
{
    _detail = baseException.Message 
        + System.Environment.NewLine + System.Environment.NewLine 
        + "Soap Detail: " + Mask.NullString(soapException.Detail.InnerText) 
        + System.Environment.NewLine + System.Environment.NewLine 
        + "Regular detail: " + System.Environment.NewLine + _detail;
    _message = Mask.NullString(soapException.Detail.InnerText);
    // not sure how big these detail strings get, so arbitrarily cap the size on the short message
    if (_message.Length > 100)
    {
        _message = _message.Substring(0, 100);
    }
}

And now I get Elmah error logs like:

Instead of:

And detail messages like:

Instead of: