Where did the h1 element with the text CatPhotoApp go?
Be careful to only make the changes that the instructions ask you to make. The instruction did not ask you to remove the h1 element and so you should have left it there. Making any unexpected changes will usually cause the tests to fail.
You might want to restart the step to get the original HTML back and then make sure to only add the new h2 element and not do anything else.