Updating Collaborate package with Collaborate Window open and selecting 'Open Changes/History' Panel from Project Settings turns the Collaborate Window blank and throws NullReference Exceptions until the Collab Window is closed and reopened.
Refer to the attached Video.

Steps to Reproduce:
1. Create a New Project
2. Edit > Project Settings > Services > Collaborate > Set Organization > Create Project ID
3. Project Settings > Services > Collaborate > ON
4. Project Settings > Services > Collaborate > Open Changes/History Panel
5. Windows > Package Manager > Unity Collaborate > Update ([2.0.0-p17] OR [2.1.0-p3]) (Observe Result 1)
6. Repeat Step 4 (Observe Result 2)
7. Close and Reopen Collaborate Window
8. Project Settings > Services > Collaborate > Install Latest Package (1.3.7) (Observe Result 1)
9. Repeat Step 4 (Observe Result 2)

Actual Results:
1. Collaborate Window turns blank (occurs only with [2.1.0-p3], [2.0.0-p17] distorts the window)
2. NullReference Exceptions are displayed in the console

Expected Result:
Collaborate Window should retain its information and not throw errors in the console on opening Changes/History panel

Occurring on:
2020.2.0a5 with 2.1.0-p3, 2.0.0-p17, 2.0.0-p6, 1.3.7
2020.1.0b4 with 2.1.0-p3, 2.0.0-p17, 1.3.7
2020.1.0a22 with 2.1.0-p3, 2.0.0-p17, 1.3.7

Working Fine on:
2020.1.0a22 with 1.3.6
2020.1.0a21 with 1.3.5, 1.3.6
2020.1.0a17 with 1.3.6, 1.3.2
2020.1.0a16 with 1.2.16, 1.3.6

Notes:
1. Couldn't test 2019.3.8f1 as it did not have the 1.3.x package versions
2. 2020.1.0a17 was introduced with 1.3.6 as Verified as opposed to 1.2.16 in 2020.1.0a16
3. The Open Changes/History Panel link from the Project Settings was broken till 2020.1.0a21

Environment:
Windows 10 and macOS 10.14

----------------------Stack Trace----------------------

NullReferenceException: Object reference not set to an instance of an object
Unity.Cloud.Collaborate.UserInterface.CollaborateWindow.RequestFocus (Unity.Cloud.Collaborate.UserInterface.CollaborateWindow+FocusTarget focusTarget) (at Library/PackageCache/com.unity.collab-proxy@1.3.7/Editor/UserInterface/CollaborateWindow.cs:198)
Unity.Cloud.Collaborate.UserInterface.CollaborateWindow.Init (Unity.Cloud.Collaborate.UserInterface.CollaborateWindow+FocusTarget focusTarget) (at Library/PackageCache/com.unity.collab-proxy@1.3.7/Editor/UserInterface/CollaborateWindow.cs:77)
CollabProxy.UI.Bootstrap+<>c.<.cctor>b__0_1 () (at Library/PackageCache/com.unity.collab-proxy@1.3.7/Editor/UserInterface/Bootstrap.cs:25)
UnityEditor.Connect.CollabProjectSettings+EnabledState+<>c.<EnterState>b__4_1 () (at <92f998fbb4ca4d8dab7793d6e003b794>:0)
UnityEngine.UIElements.Clickable.Invoke (UnityEngine.UIElements.EventBase evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.Clickable.ProcessUpEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.Vector2 localPosition, System.Int32 pointerId) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.Clickable.OnMouseUp (UnityEngine.UIElements.MouseUpEvent evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventCallbackFunctor`1[TEventType].Invoke (UnityEngine.UIElements.EventBase evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventCallbackRegistry.InvokeCallbacks (UnityEngine.UIElements.EventBase evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.CallbackEventHandler.HandleEvent (UnityEngine.UIElements.EventBase evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.CallbackEventHandler.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.MouseCaptureDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.OpenGate () (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcherGate.Dispose () (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <e40488dcb2e3475fad9ef37a4468eea0>:0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <faa31f22dbbe43159226eb3a4f009ff2>:0)

----------------------End of Stack Trace----------------------