Category.php in child theme causes Admin toolbar to disappear

I’m making a child theme of twenty twelve. I want to make a modification to the category.php file, but have come across a couple of problems and I have no idea what’s causing the problems.

The problems occur as soon as I copy the twenty twelve’s category.php file to my child theme’s folder. I have made no change to the category.php file at this point. It is just a copy. I verified that these issues go away as soon as I delete the category.php file from my child theme folder and reappear when I copy the file back. I have verified that I am using the original twenty twelve theme’s category.php file.

The issues are:

1. The Admin Toolbar disappears when viewing a category. It reappears when viewing a different page/post, but disappears as soon as I try displaying a category.

2. I have added a slideshow to header.php file. The slideshow displays on pages, posts and categories, until I copy the unmodified category.php file to the child theme. At that point the slideshow disappears (along with the admin toolbar) on the category page.

I’m still trying to resolve the issue so not sure how long this link will display the issue. Also, the admin toolbar will only display if logged in, but you can see the behavior of the slideshow.

link to category: https://ajanafitness.com/category/articles/
link to a page: https://ajanafitness.com/rachel/

Thanks for any help!
Tammy