Looks like Entities Hierarchy easily to stop working after code compilation. Sometimes will fix after enter playmode but sometimes needs to restart editor
Unity.Entities.Editor.HierarchyWindow.OnWorldSelected (Unity.Entities.World world) (at ./Library/PackageCache/com.unity.entities@1.0.11/Unity.Entities.Editor/Hierarchy/HierarchyWindow.cs:396)
Unity.Entities.Editor.DOTSEditorWindow.Update () (at ./Library/PackageCache/com.unity.entities@1.0.11/Unity.Entities.Editor/Common/DOTSEditorWindow.cs:193)
UnityEditor.HostView.SendUpdate () (at <da771086bc2e4cfc9ad0a72e083a7f98>:0)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <da771086bc2e4cfc9ad0a72e083a7f98>:0)
Unity.Entities.Editor.HierarchyWindow.OnUpdate () (at ./Library/PackageCache/com.unity.entities@1.0.11/Unity.Entities.Editor/Hierarchy/HierarchyWindow.cs:415)
Unity.Entities.Editor.DOTSEditorWindow.Update () (at ./Library/PackageCache/com.unity.entities@1.0.11/Unity.Entities.Editor/Common/DOTSEditorWindow.cs:196)
UnityEditor.HostView.SendUpdate () (at <da771086bc2e4cfc9ad0a72e083a7f98>:0)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at <da771086bc2e4cfc9ad0a72e083a7f98>:0)