Exception on timer

When working with ORIGAM Architect, if the Deployment Script Generator is open and there is an external change in the model, following error is raised:

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Error
Exception on timer
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Exception on timer
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Value cannot be null.
Parameter name: input
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 Stack trace
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   at System.Guid.Parse(String input)
   at OrigamArchitect.frmMain.<>c__DisplayClass134_0.<ShouldRaiseWarning>b__0(IViewContent view)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source, Func`2 predicate)
   at OrigamArchitect.frmMain.OnFilePersistServiceReloadRequested(Object sender, ChangedFileEventArgs args)
   at Origam.DA.Service.FileEventQueue.ProcessAccumulatedEvents()
   at Origam.DA.Service.FileEventQueue.TimerElapsedHandler()   at Origam.DA.Service.FileEventQueue.<>c__DisplayClass15_0.<TimerElapsedHandler>b__0(Object _)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()

Fixed in master build 4972