Undo won't work

I am new to 2.0.06. After making new tracks etc., when I make a mistake and clk on the Undo icon nothing happens. Why?
Also, how do I undo a track than I do not want?

Most tools only work from Stop. If you try it from Pause, it may not work.
Koz

You can remove a track using the button top left of the track.


Gale