Doesn't reproduce in 2019.1.11f1
Reproduced in 2019.2.6f1, 2019.3.0b3, and 2020.1.0a4 (both 6.0.1 and 6.1.1)
Repro steps:
1. Use a project with Universal
2. Create a new PBR shadergraph
3. Navigate to the folder the shadergraph is in
4. Open the shadergraph file in your text editor of choice
5. Add an extra curly brace ("{") to the beginning of the file and save it
6. Switch back to Unity
Expected result: Unity will not crash but the shadergraph will become invalid and the console will print a Json Parse Error
Actual result: Unity not only crashes, but doesn't run the crash handler, so there is no way to report the crash properly

I've attached the crash logs, but since Unity does not run the crash handler there's a chance that it doesn't write the final crash data to the logs either.