On closing "Simple Swarm Particle System" Template which has a reconverted "Subgraph Operator" Node causes the editor to quit, refer attached video

Steps to repro:
1. Create a new project
2. Windows > Package Manager > Visual Effects Graph > Install
3. Project > Packages > Visual Effect Graph > Editor > Templates > Open Simple Swarm Particle System
4. Add any "Node" to any block
5. Select Node > right-click > Convert to Subgraph Operator > Save
6. Select same converted node > right-click > Convert to Subgraph Operator > Save > Replace(yes)
7. Closed "Open Simple Swarm Particle System" Template

Actual Result:
Editor quits on closing "Simple Swarm Particle System" Template When "Subgraph Operator Node" has been reconverted twice

Expected Result:
"Simple Swarm Particle System" Template closes gracefully and even has a reconverted "Subgraph Operator Node"

Reproducible in:
2020.1.0a6, 2019.3.0b4

Working fine on:
2019.3.0b3, 2019.3.0a10

Package version found: 7.1.2, 7.1.1

Package version working fine: 7.0.1, 7.0.0

NOTE:
Visual Effect Graph is introduced in 2019.3.0a10.

Environment:
Windows 10 & macOS 10.14