If an expression is added from the Register view via right-click and selecting "Watch", that expression will be successfully added to the Expressions view. However, this puts the Expressions view into a bad state where attempting to add additional expressions (whether via Register view or manually from the Expressions view) will appear to not work or simply add a new "Add new expression" field. A refresh of the view will then correctly update the view to display the correct information. This is the case for every time you add/remove an expression from the Expressions view. This issue is triggered only after an expression is first added from the Register view using the technique mentioned earlier.