1. Create a launch L1 from any page as a source.
2. then create another nested launch L2 with source as L1
3. then create another nested launch L3 with source as L2.
4. Delete L2 launch from launch console.
5. Following error comes in console and Launch Console doesn't get opened.
6. Uncaught TypeError: Cannot read property 'dataset' of null.
I have deleted child launch L3 of deleted launch L2 from /content/launches in CRXDE, Then launch console get opened.