打开体验编辑器时遇到问题。体验编辑器遇到错误：
Tracker.Current未初始化。
有人遇到吗？
下面是错误日志：
7712 06:11:08 ERROR Cannot create tracker.
Exception: System.InvalidOperationException
Message: Could not find type 'Sitecore.Modules.EmailCampaign.Core.Pipelines.EnsureSessionContext.LoadEmailRenderSessionContact, Sitecore.EmailCampaign'
Source: Sitecore.Kernel
at Sitecore.Configuration.DefaultFactory.CreateFromServiceProvider(XmlNode configNode, Boolean assert)
at Sitecore.Configuration.DefaultFactory.CreateObject(XmlNode configNode, String[] parameters, Boolean assert, IFactoryHelper helper)
at Sitecore.Configuration.DefaultFactory.CreateObject(XmlNode configNode, Boolean assert)
at Sitecore.Pipelines.CorePipelineFactory.GetObjectFromType(XmlNode processorNode)
at Sitecore.Pipelines.CorePipelineFactory.GetProcessorObject(XmlNode processorNode)
at Sitecore.Pipelines.CoreProcessor.GetMethod(Object[] parameters)
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Analytics.Pipelines.EnsureSessionContext.EnsureSessionContextPipeline.<>c__DisplayClass4_0.<Run>b__0()
at Sitecore.Analytics.XConnect.Diagnostics.PerformanceCounters.OperationPerformanceMonitorExtensions.<>c__DisplayClass1_0.<Monitor>b__0()
at Sitecore.Analytics.XConnect.Diagnostics.PerformanceCounters.OperationPerformanceMonitorExtensions.Monitor[T](OperationPerformanceMonitorBase monitor, Func`1 operation)
at Sitecore.Analytics.DefaultTracker.EnsureSessionContext()
at Sitecore.Analytics.Pipelines.CreateTracker.GetTracker.Process(CreateTrackerArgs args)
at (Object , Object[] )
at Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args)
at Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain)
at Sitecore.Analytics.Tracker.Initialize()