ERD crashing (#465)

Every time I try to create an ERD (even in a brand new file), and then try to pull up field properties, I get the following error:

System.AggregateException: One or more errors occurred. ---> System.NullReferenceException: Object reference not set to an instance of an object.

at SoftwareIdeasModeler.Core.DiagramItems.ErdItems.ErdEntityAttribute.GetFieldIndex()

at SoftwareIdeasModeler.Core.Projecting.DiagramNavigableField..ctor(IConcreteDiagramElement parent, ConcreteField concreteField)

at SoftwareIdeasModeler.Core.Projecting.ConcreteDiagramElement.<GetField>b__323_1(ConcreteField concreteField)

at System.Linq.Parallel.SelectQueryOperator`2.SelectQueryOperatorEnumerator`1.MoveNext(TOutput& currentElement, TKey& currentKey)

at System.Linq.Parallel.FirstQueryOperator`1.FirstQueryOperatorEnumerator`1.MoveNext(TSource& currentElement, Int32& currentKey)

at System.Linq.Parallel.StopAndGoSpoolingTask`2.SpoolingWork()

at System.Linq.Parallel.SpoolingTaskBase.Work()

at System.Linq.Parallel.QueryTask.BaseWork(Object unused)

at System.Threading.Tasks.Task.Execute()

--- End of inner exception stack trace ---

at System.Linq.Parallel.QueryTaskGroupState.QueryEnd(Boolean userInitiatedDispose)

at System.Linq.Parallel.DefaultMergeHelper`2.System.Linq.Parallel.IMergeHelper<TInputOutput>.Execute()

at System.Linq.Parallel.MergeExecutor`1.Execute[TKey](PartitionedStream`2 partitions, Boolean ignoreOutput, ParallelMergeOptions options, TaskScheduler taskScheduler, Boolean isOrdered, CancellationState cancellationState, Int32 queryId)

at System.Linq.Parallel.PartitionedStreamMerger`1.Receive[TKey](PartitionedStream`2 partitionedStream)

at System.Linq.Parallel.FirstQueryOperator`1.WrapHelper[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, QuerySettings settings)

at System.Linq.Parallel.FirstQueryOperator`1.WrapPartitionedStream[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream)

at System.Linq.Parallel.WhereQueryOperator`1.WrapPartitionedStream[TKey](PartitionedStream`2 inputStream, IPartitionedStreamRecipient`1 recipient, Boolean preferStriping, QuerySettings settings)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.ChildResultsRecipient.Receive[TKey](PartitionedStream`2 inputStream)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient)

at System.Linq.Parallel.UnaryQueryOperator`2.UnaryQueryOperatorResults.GivePartitionedStream(IPartitionedStreamRecipient`1 recipient)

at System.Linq.Parallel.QueryOperator`1.GetOpenedEnumerator(Nullable`1 mergeOptions, Boolean suppressOrder, Boolean forEffect, QuerySettings querySettings)

at System.Linq.Parallel.QueryOpeningEnumerator`1.OpenQuery()

at System.Linq.Parallel.QueryOpeningEnumerator`1.MoveNext()

at System.Linq.ParallelEnumerable.GetOneWithPossibleDefault[TSource](QueryOperator`1 queryOp, Boolean throwIfTwo, Boolean defaultIfEmpty)

at System.Linq.ParallelEnumerable.FirstOrDefault[TSource](ParallelQuery`1 source)

at SoftwareIdeasModeler.Core.Projecting.ConcreteDiagramElement.GetFieldAtNormalized(Point location)

at SoftwareIdeasModeler.Core.DiagramItems.ErdItems.ConcreteErdEntity.GetFieldAtNormalized(Point location)

at SoftwareIdeasModeler.Core.Diagramming.Canvas.CanvasProcessor.SetHoverField(IConcreteDiagramElement element, Point location)

at SoftwareIdeasModeler.Core.Diagramming.Canvas.CanvasProcessor.SetHoverField(Point location, List`1 overElements)

at SoftwareIdeasModeler.Core.Diagramming.Canvas.CanvasProcessor.MouseMove(Point location, Point screenLocation, PenModifiers modifiers)

at SoftwareIdeasModeler.SimDiagramControl.canvas_MouseMove(Object sender, MouseEventArgs e)

at System.Windows.Forms.Control.OnMouseMove(MouseEventArgs e)

at System.Windows.Forms.Control.WmMouseMove(Message& m)

at System.Windows.Forms.Control.WndProc(Message& m)

at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

---> (Inner Exception #0) System.NullReferenceException: Object reference not set to an instance of an object.

at SoftwareIdeasModeler.Core.DiagramItems.ErdItems.ErdEntityAttribute.GetFieldIndex()

at SoftwareIdeasModeler.Core.Projecting.DiagramNavigableField..ctor(IConcreteDiagramElement parent, ConcreteField concreteField)

at SoftwareIdeasModeler.Core.Projecting.ConcreteDiagramElement.<GetField>b__323_1(ConcreteField concreteField)

at System.Linq.Parallel.SelectQueryOperator`2.SelectQueryOperatorEnumerator`1.MoveNext(TOutput& currentElement, TKey& currentKey)

at System.Linq.Parallel.FirstQueryOperator`1.FirstQueryOperatorEnumerator`1.MoveNext(TSource& currentElement, Int32& currentKey)

at System.Linq.Parallel.StopAndGoSpoolingTask`2.SpoolingWork()

at System.Linq.Parallel.SpoolingTaskBase.Work()

at System.Linq.Parallel.QueryTask.BaseWork(Object unused)

at System.Threading.Tasks.Task.Execute()<---

OF=SoftwareIdeasModeler.MainForm

LastCmd=SoftwareIdeasModeler.Core.Commands.ChangeErdAttributeCommand

OF=SoftwareIdeasModeler.Forms.StartForm

OF=SoftwareIdeasModeler.Forms.ProjectForm

OF=SoftwareIdeasModeler.Forms.EditorForm