Thank you, Helen for this great class.

Here are my wavy lines

 

The skyline one without outline works well

 

But I really have a problem when I want to add an outline : I get an horrible result : a line in the middle and I lost some colors ...

 

Below my artboard, the outlines are outside the shapes and outside the artboard, I tried to reduce as much as I can the width (248px, then 246px and finally 244px instead of 250) of the no fill no stroke rectangle selected in the screenshot so you can view it, but nothing changes.

 

My layers seem correct :

I'm totally perplex ...

Thank you for your help :-)

 

Outline - 2° try

 

Thank you, Helen, for your help.

As you told me, I deleted the "outline" layer and made a new outlined pattern from the original one.

And now it works perfectly :-)

I'll remember the lesson : sometimes we gain time when beginning again from 0  :-)