UXML importer fails to detect invalid UXML field and then results in ArgumentException in UIBuilder

To reproduce, open the attached project and open the UI Builder window. Notice the argument exception in the console:

ArgumentException: Requested value 'Right' was not found.
at System.Enum+EnumResult.SetFailure (System.Enum+ParseFailureKind failure, System.String failureMessageID, System.Object failureMessageFormatArgument) [0x00023] in <a35250a304174d009b77e5c5f6695f54>:0
at System.Enum.TryParseEnum (System.Type enumType, System.String value, System.Boolean ignoreCase, System.Enum+EnumResult& parseResult) [0x0017a] in <a35250a304174d009b77e5c5f6695f54>:0
at System.Enum.Parse (System.Type enumType, System.String value, System.Boolean ignoreCase) [0x00010] in <a35250a304174d009b77e5c5f6695f54>:0
at System.Enum.Parse (System.Type enumType, System.String value) [0x00000] in <a35250a304174d009b77e5c5f6695f54>:0
at Unity.UI.Builder.BuilderInspectorStyleFields.RefreshStyleFieldValue (System.String styleName, UnityEngine.UIElements.VisualElement fieldElement, System.Boolean forceInlineValue) [0x00dbb] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderInspectorStyleFields.RefreshStyleField (System.String styleName, UnityEngine.UIElements.VisualElement fieldElement) [0x0000f] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderInspectorLocalStyles.Refresh () [0x001bc] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderInspector.RefreshUI () [0x0038d] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderInspector.SelectionChanged () [0x001b1] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderSelection.NotifyOfSelectionChange (Unity.UI.Builder.IBuilderSelectionNotifier source) [0x00068] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderSelection.Select (Unity.UI.Builder.IBuilderSelectionNotifier source, UnityEngine.UIElements.VisualElement ve) [0x00088] in <0b41136f58854a5aafa95804e773dfb7>:0
at Unity.UI.Builder.BuilderViewport.OnPick (UnityEngine.UIElements.MouseDownEvent evt) [0x00063] in <0b41136f58854a5aafa95804e773dfb7>:0
at UnityEngine.UIElements.EventCallbackFunctor`1[TEventType].Invoke (UnityEngine.UIElements.EventBase evt) [0x00010] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventCallbackRegistry+DynamicCallbackList.Invoke (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.VisualElement target) [0x0008f] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventDispatchUtilities.HandleEventAcrossPropagationPathWithCompatibilityEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.EventBase compatibilityEvt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.VisualElement target, System.Boolean isCapturingTarget) [0x002ed] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventDispatchUtilities.DispatchToCachedElementUnderPointerOrPanelRoot (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, System.Int32 pointerId, UnityEngine.Vector2 position) [0x00037] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventDispatchUtilities.DispatchToCapturingElementOrElementUnderPointer (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, System.Int32 pointerId, UnityEngine.Vector2 position) [0x0001a] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.PointerEventBase`1[T].Dispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) [0x00014] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel) [0x00039] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) [0x00046] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) [0x0001f] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) [0x00136] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) [0x0003d] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) [0x0001a] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) [0x00001] in <bab63c62b92b4842b57501a32421fc7d>:0
at UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) [0x00079] in <baaad0161ae2487a9a523a80fa313b8d>:0