Minimal component for testing

test-content-event-component.cs

using System;
using System.Linq;
using System.Web.Http.Filters;
using Umbraco.Core;
using Umbraco.Core.Composing;
using Umbraco.Web.Editors;
using Umbraco.Web.Models.ContentEditing;

namespace Foo.Bar.AppCode
{
    public class TestContentEventsComponent : IComponent
    {
        public void Initialize()
        {
            EditorModelEventManager.SendingContentModel += EditorModelEventManager_SendingContentModel;
        }

        public void Terminate()
        {
            EditorModelEventManager.SendingContentModel -= EditorModelEventManager_SendingContentModel;
        }

        /// <summary>
        /// Remove the workflow app if the node is exclude or has no content app
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void EditorModelEventManager_SendingContentModel(HttpActionExecutedContext sender, EditorModelEventArgs<ContentItemDisplay> e)
        {
            try
            {
                var apps = e.Model.ContentApps;

                // on 1.4.3, this is the line throwing the error
                if (!e.Model.IsElement && apps != null && apps.Any(a => a.Alias == "umbContent"))
                {
                    return;
                }
            }
            catch(Exception ex)
            {
                Current.Logger.Error(typeof(TestContentEventsComponent), ex, ex.Message);
            }
        }
    }

    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
    public class TestComposer : IUserComposer
    {
        public void Compose(Composition composition)
        {
            composition.Components()
                .Append<TestContentEventsComponent>();
        }
    }
}