The area of the rounded rectangle is : 15958044 mm² - this is the large one on the right hand side of the image

Hi guys am new here but wanting to learn about SketchUp!

I wanted to create a rounded cube so followed this video guide:

But my result looks like this :

It seems to go wrong when I "Follow Me" - as seen in the picture the odd meshing of the top components looks wrong - and perhaps is why its broken - but I am not sure where in the video I am making this mistake!

Please help