Delete molecule using Delete key caused error

[seongsangcho-hits]

Deleting a molecule when there is only one molecule left on the canvas will cause an error.

• "Exception caught: (TypeError) : Cannot read properties of null (reading 'Q')"

[jsme-editor]

I can see the error when trying to delete the last atom of the single molecule on the canvas.

[inghylt]

We're experiencing the same problem in our project