NullReferenceException thrown on selecting package Manifest of TextMeshPro. Exceptions are coming on selecting other packages also after selecting TextMeshPro package Manifest file

Steps to Repro:
1. Open a new Project
2. Select Window > PackageManager > Sort : Publish date
3. Select Assets > Packages > TextMeshPro > package Manifest

Expected Result:
No error in the Console

Actual Result:
NullReferenceException thrown on selecting package Manifest of TextMeshPro

Reproducible on: 2020.2.0a5

Working fine on: 2020.2.0a4, 2020.1.0b3, 2019.3.6f1

Environment: Windows 10 and Mac 10.14

Stack Trace:

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.PackageManager.PackageManifestImporterEditor.DrawDependencyListElement (UnityEngine.Rect rect, System.Int32 index, System.Boolean isActive, System.Boolean isFocused) (at <89faf899e9c14826b38ffd64a0c1974d>:0)
UnityEditorInternal.ReorderableList.DoListElements (UnityEngine.Rect listRect) (at <89faf899e9c14826b38ffd64a0c1974d>:0)
UnityEditorInternal.ReorderableList.DoLayoutList () (at <89faf899e9c14826b38ffd64a0c1974d>:0)
UnityEditor.PackageManager.PackageManifestImporterEditor.OnInspectorGUI () (at <89faf899e9c14826b38ffd64a0c1974d>:0)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass58_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <89faf899e9c14826b38ffd64a0c1974d>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)