Open a project but stay on main menu if project doesn't have "mainUiFile:" defined

To avoid having the Live Preview opening the mainFile/mainUiFile instead of the current view, I comment those 2 lines in the qmlproject file. But now every time I open the project, instead changing view to code edit, I stay on the main menu will the project is now open in the back.

If I do "Ctrl-2" to change view, the view will change and the project is correctly loaded.

If instead I reselect the project on the main menu, an error will be displaying saying that it cannot open a directory as a file and stay on the main menu.

And if instead I open the project again but with "Open" or "Open project", the view will now correctly be change.