Issue: after updating a UAT server I was getting the following error in the “item:deleted” event after trying to publish anything…

Job started: Publish to 'web'|#Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.AggregateException: One or more exceptions occurred while processing the subscribers to the 'item:deleted' event.
at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters, EventResult result)
at Sitecore.Events.Event.RaiseEvent(String eventName, Object[] parameters)
at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
at Sitecore.Data.Engines.EngineCommand`2.RaiseEvent[TArgs](EventHandler`1 handlers, Func`2 argsCreator)
at Sitecore.Data.Engines.EngineCommand`2.Execute()
at Sitecore.Data.Engines.DataEngine.DeleteItem(Item item)
at Sitecore.Publishing.PublishHelper.DeleteTargetItem(ID itemId)
at Sitecore.Publishing.Pipelines.PublishItem.PerformAction.ExecuteAction(PublishItemContext context)
at Sitecore.Publishing.Pipelines.PublishItem.PerformAction.Process(PublishItemContext context)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Publishing.Pipelines.PublishItem.PublishItemPipeline.Run(PublishItemContext context)
at Sitecore.Publishing.Pipelines.Publish.ProcessQueue.ProcessPublishingCandidate(PublishingCandidate entry, PublishContext context, List`1& referrers, List`1& children)
at Sitecore.Publishing.Pipelines.Publish.ProcessQueue.ProcessPublishingCandidate(PublishingCandidate entry, PublishContext context)
at Sitecore.Publishing.Pipelines.Publish.ProcessQueue.ProcessEntries(IEnumerable`1 entries, PublishContext context)
at Sitecore.Publishing.Pipelines.Publish.ProcessQueue.Process(PublishContext context)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Publishing.Pipelines.Publish.PublishPipeline.Run(PublishContext context)
at Sitecore.Publishing.Publisher.PublishWithResult()
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Sitecore.Reflection.ReflectionUtil.InvokeMethod(MethodInfo method, Object[] parameters, Object obj)
at Sitecore.Jobs.JobRunner.RunMethod(JobArgs args)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Jobs.Job.ThreadEntry(Object state)

Nice. Okay, looking at the item deleted event, I found we had two additional handlers for Email Experience Manager.

<handler type="Sitecore.Modules.EmailCampaign.Core.RootItemEventHandler, Sitecore.EmailCampaign" method="OnRootDeleted" patch:source="Sitecore.EmailExperience.ContentManagement.config"/>
<handler type="Sitecore.Modules.EmailCampaign.Core.ItemEventHandler, Sitecore.EmailCampaign" method="OnItemDeleted" patch:source="Sitecore.EmailExperience.ContentManagement.config"/>

I commented those out, republished, and it worked just fine. Not ideal – I don’t know why they had an issue – but it unblocked me.