> No questions are asked: this is a deliberate design decision, which needs getting used to. Most editors ask the user when closing a modified text: this is not the case in the Oberon System.
For the case of accidentally closing a Viewer: The command System.Recall restores the most recently closed Viewer. Just find or type that command anywhere on the screen and then execute it by clicking it with the middle mouse button.
I wonder how the system deals with user errors…