Initialize action failed for Initialize on class Episerver.Marketing.Connector.Framework.MarketingConnectorInitialization

Description

Steps to reproduce:
1. Set up an Alloy sample project, all packages updated.
2. Install EPiServer.ConnectForMarketingAutomation package version 5.0.1.
3. Deploy the site locally.

Expected:
The site works as normal.

Actual:
The site cannot start. Exception message is thrown:

[ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.]
   System.Reflection.RuntimeModule.GetTypes(RuntimeModule module) +0
   System.Reflection.Assembly.GetTypes() +112
   System.Linq.<SelectManyIterator>d__17`2.MoveNext() +295
   System.Linq.WhereEnumerableIterator`1.MoveNext() +51
   Episerver.Marketing.Connector.Framework.Helpers.ReflectionHelper.GetInstances(IEnumerable`1 typeCollection) +133
   Episerver.Marketing.Connector.Framework.MarketingConnectorManager.GetConnectors() +146
   Episerver.Marketing.Connector.Framework.MarketingConnectorManager.GetActiveConnectors() +51
   Episerver.Marketing.Connector.Framework.MarketingConnectorManager.CacheActiveConnectorData() +36
   Episerver.Marketing.Connector.Framework.MarketingConnectorInitialization.Initialize(InitializationEngine context) +73
   EPiServer.Framework.Initialization.Internal.ModuleNode.Execute(Action a, String key) +58
   EPiServer.Framework.Initialization.Internal.ModuleNode.Initialize(InitializationEngine context) +123
   EPiServer.Framework.Initialization.InitializationEngine.InitializeModules() +248
 
[InitializationException: Initialize action failed for Initialize on class Episerver.Marketing.Connector.Framework.MarketingConnectorInitialization, Episerver.Marketing.Connector, Version=5.0.1.0, Culture=neutral, PublicKeyToken=null]
   EPiServer.Framework.Initialization.InitializationEngine.InitializeModules() +774
   EPiServer.Framework.Initialization.InitializationEngine.ExecuteTransition(Boolean continueTransitions) +194
   EPiServer.Framework.Initialization.InitializationModule.EngineExecute(HostType hostType, Action`1 engineAction) +876
   EPiServer.Framework.Initialization.InitializationModule.FrameworkInitialization(HostType hostType) +225
   EPiServer.Global..ctor() +42
   Alloy11MVC.EPiServerApplication..ctor() +43
   ASP.global_asax..ctor() in c:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\root\f989c366\1acdf1f2\App_global.asax.vuffck2g.0.cs:0
 
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0
   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +139
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +105
   System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, StackCrawlMark& stackMark) +1431
   System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) +184
   System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture) +27
   System.Web.HttpRuntime.CreateNonPublicInstance(Type type, Object[] args) +79
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +262
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +341
 
[HttpException (0x80004005): Exception has been thrown by the target of an invocation.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +523
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +107
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +688