NullReferenceException happening when window is closed but enabled

[rarepops]

1. NullReferenceException: Object reference not set to an instance of an object
2. UnityEditor.EditorIterationProfiler.IterationEventRoot.SetParent (UnityEditor.EditorIterationProfiler.EventData child, UnityEditor.EditorIterationProfiler.EventData parent) (at Packages/com.unity.editoriterationprofiler-0.1.1-preview/Editor/IterationEventRoot.cs:126)
3. UnityEditor.EditorIterationProfiler.IterationEventRoot.AddChildEvent (System.String identifier, System.String metadata, System.Double startTime, System.Double finishTime, UnityEditor.EditorIterationProfiler.EventData parentEvent, UnityEditor.EditorIterationProfiler.EventDataFlags flags) (at Packages/com.unity.editoriterationprofiler-0.1.1-preview/Editor/IterationEventRoot.cs:108)
4. UnityEditor.EditorIterationProfiler.ProfilerDataCollector.ReadProfilingData (UnityEditor.EditorIterationProfiler.IterationEventRoot iterationEventRoot, UnityEditor.EditorIterationProfiler.EventData parentEventData, UnityEditor.Profiling.HierarchyFrameDataView frameData, System.Int32 sampleId, UnityEditor.EditorIterationProfiler.EventDataFlags flags, System.Boolean parentHasSingleChild) (at Packages/com.unity.editoriterationprofiler-0.1.1-preview/Editor/ProfilerDataCollector.cs:272)
5. UnityEditor.EditorIterationProfiler.ProfilerDataCollector.ProfilerNewFrame (System.Int32 connectionId, System.Int32 newFrameIndex) (at Packages/com.unity.editoriterationprofiler-0.1.1-preview/Editor/ProfilerDataCollector.cs:220)
6. UnityEditorInternal.ProfilerDriver.InvokeNewProfilerFrameRecorded (System.Int32 connectionId, System.Int32 newFrameIndex) (at :0)

However, it could just be the case there's some missing root in the hierarchy.