'Value' must be a double scalar.

% the program send me that message when I run the interface
value = app.tasaX.Value; % this is a list box with nouns which have an associeted number
            app.a.Value = value; %this is the editfield numeric where I can't see the number of the listbox and send me that message 'Value' must be a double scalar.

[Rik]

What does this return?

disp(class(app.tasaX.Value)),disp(app.tasaX.Value)