Beta 3 and 4 both crash every time

I upgraded Logos 3 to Logos 4 on beta 1 and everything worked great. But now both Beta 3 and Beta 4 are crashing every time I attempt to run it.

I'm running Windows 7. Here's the exception detail.

System.NullReferenceException was unhandled

  Message="Object reference not set to an instance of an object."

  Source="Libronix.DigitalLibrary.Resources"

  StackTrace:

       at Libronix.DigitalLibrary.Resources.Excerpts.ExcerptResourceCore.CreateExcerpt(ResourceManager resourceManager, ExcerptEntity excerpt)

       at Libronix.DigitalLibrary.Resources.Excerpts.ExcerptResourceCore.GetExcerptFromEntityId(ResourceManager resourceManager, Int64 nEntityId)

       at Libronix.DigitalLibrary.Resources.Excerpts.ExcerptResource.GetExcerptFromEntityId(ResourceManager resourceManager, Int64 nEntityId)

       at LDLS4.HomePage.ExcerptHomePageItemProvider.GetExcerpt(ExcerptResource resource, Int64 nExcerptEntityId)

       at LDLS4.HomePage.ExcerptHomePageItemProvider.GenerateItem(ExcerptResource resource, Int64 nExcerptEntityId)

       at LDLS4.HomePage.ExcerptHomePageItemProvider.GenerateItemsCore()

       at LDLS4.HomePage.HomePageItemProvider.GenerateItems()

       at LDLS4.HomePage.HomePageViewModel.<>c__DisplayClass27.<GenerateItemsWork>b__14(Object prov)

       at Libronix.Utility.Threading.DelegateAsyncWorkItem.<ExecuteCore>b__0(Object o)

       at System.Threading.ExecutionContext.runTryCode(Object userData)

       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)

       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)

       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

       at Libronix.Utility.Threading.DelegateAsyncWorkItem.ExecuteCore()

       at Libronix.Utility.Threading.AsyncWorkItem.Execute()

       at Libronix.Utility.Threading.ThreadPoolAsyncWorkItem.<StartCore>b__0(Object o)

       at Libronix.Utility.Threading.GroupedThreadPool.ExecuteNextCallback(Object state)

       at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)

       at System.Threading.ExecutionContext.runTryCode(Object userData)

       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)

       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)

       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

       at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)

       at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)

  InnerException: