-NullReferenceException is thrown on changing the name property of the "Screen Space Ambient Occlusion" Renderer Feature.
-ArgumentNullException is thrown on changing the name property of the "Screen Space Shadow" & "Render Object" Renderer Feature.

Steps to repro:
1. Create a new URP template project.
2. Project Window > Click on "+" > Rendering.
3. Universal Render Pipeline > Forward Renderer > Add Renderer Feature.
4. Screen Space Ambient Occlusion > Change Name > Test1.

Actual Result:
NullReferenceException is thrown in the console.

Expected Result:
No errors in the console.

Reproducible in:
2021.2.0a6, 2021.2.0a5 with Package Version 12.0.0.
2021.1.0b8 with Package Version 11.0.0.
2020.2.7f1, 2020.2.6f1 with Package Version 10.3.1.

Working Fine in:
2021.2.0a4 with Package Version 12.0.0.
2021.1.0b7 with Package version 11.0.0.
2020.2.5f1 with Package Version 10.3.1.

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
NullReferenceException: SerializedObject of SerializedProperty has been Disposed.
UnityEditor.SerializedProperty.get_propertyType () (at <5c963931ea5c41c59d3071fbccd30e0e>:0)
UnityEditor.EditorGUILayout.IsChildrenIncluded (UnityEditor.SerializedProperty prop) (at <5c963931ea5c41c59d3071fbccd30e0e>:0)
UnityEditor.EditorGUILayout.PropertyField (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, UnityEngine.GUILayoutOption[] options) (at <5c963931ea5c41c59d3071fbccd30e0e>:0)
UnityEditor.Rendering.Universal.ScreenSpaceAmbientOcclusionEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@11.0.0/editor/rendererfeatures/screenspaceambientocclusioneditor.cs:54)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.DrawRendererFeature (System.Int32 index, UnityEditor.SerializedProperty& renderFeatureProperty) (at library/packagecache/com.unity.render-pipelines.universal@11.0.0/editor/scriptablerendererdataeditor.cs:134)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.DrawRendererFeatureList () (at library/packagecache/com.unity.render-pipelines.universal@11.0.0/editor/scriptablerendererdataeditor.cs:83)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@11.0.0/editor/scriptablerendererdataeditor.cs:64)
UnityEditor.Rendering.Universal.ForwardRendererDataEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@11.0.0/editor/forwardrendererdataeditor.cs:129)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass59_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <caa0e7e7e4b34e7ba68f299ef1e5e144>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)