Bug 2019.3.13f1 UnityEditor.ContainerWindow.NotDockedWindowID Null Reference Exception

In 2019.3.13f1 after saving this exception occurs everytime in my other project too.
In ContainerWindow.cs this function gives exception. I don't know which line cause it

Code (CSharp):

1. private string NotDockedWindowID()
2. {
3.   if (!this.IsNotDocked())
4.     return (string) null;
5.   HostView hostView = this.rootView as HostView;
6.   if ((UnityEngine.Object) hostView == (UnityEngine.Object) null)
7.   {
8.     if (!(this.rootView is SplitView))
9.       return this.rootView.GetType().ToString();
10.     hostView = (HostView) this.rootView.children[0];
11.   }
12.   return (uint) this.rootView.children.Length > 0U ? (this.m_ShowMode == 2 || this.m_ShowMode == 5 ? hostView.actualView.GetType().ToString() : ((DockArea) this.rootView.children[0]).m_Panes[0].GetType().ToString()) : hostView.actualView.GetType().ToString();
13. }

 

Anyone?

 

I have the same problem.
It occurs in 2019.3.10f1 to 2019.3.14f1.
This will not occur in 2019.3.9f1.

1、Install VisualEffectGraph from PackageManager and create NewVFX.
2、Adjust the content of NewVFX.
3, Save the project.

At this time, a NotDockedWindowID Null Reference will be raised.

 

Heya, folks.

Any update on this issue?
For me It occurs in 2019.3.13f1 during build.

 

Using version 2019.3.15f1 didn't work.

 

Sorry.
The problem I was experiencing in my environment was resolved by unchecking the following.

Preferences → General → Verify Saving Assets