Hi all,

For handeling the 404 not found pages of my application i created an ApplicationEventHandler. The code is as folllows:

public class ErrorPageHandler : ApplicationEventHandler
{
    protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        LogHelper.Info<ErrorPageHandler>("application started");
        ContentFinderResolver.Current.InsertTypeBefore<ContentFinderByNotFoundHandlers, NotFoundContentFinder>();

        base.ApplicationStarting(umbracoApplication, applicationContext);
    }

    internal class NotFoundContentFinder : IContentFinder
    {
        public bool TryFindContent(PublishedContentRequest contentRequest)
        {
            LogHelper.Info<ErrorPageHandler>($"has domain {contentRequest.HasDomain}");

            if (contentRequest?.HasDomain == true)
            {
                var currentSiteRootNode = contentRequest.RoutingContext.UmbracoContext.ContentCache.GetById(contentRequest.UmbracoDomain.RootContentId.Value);
                LogHelper.Info<ErrorPageHandler>($"currentSiteNode {currentSiteRootNode}");

                if (currentSiteRootNode != null)
                {


                    var notFound = currentSiteRootNode.Descendant<NotFound>();


                    contentRequest.SetResponseStatus(404, "404 Page Not Found");

                    contentRequest.PublishedContent = notFound;
                    return contentRequest.PublishedContent != null;
                }
            }

            return false;
        }
    }
}

This code works locally, and returns my custom NotFound models' publishedContent. However, when i push this to a server, i get the generic 404 page of IIS.

When I add some debugging strings to the code, I see that this event handler is indeed ran by umbraco on a 404, and that it can find my NotFound model. I can also see that the published content is not null on the server, so the logic of the above handler (should) be fine.

What could possibly be the reason that I see the standard IIS 404 page? Umbraco can find my published content and can confirm that it is not equal to null.

Any help is appreciated.