Responsive Child Theme – page goes blank

I have the Responsive Auction Theme installed.
Wanted to install the Mobile Shop child theme.
I uploaded it via Appearance > Themes > Add new

I tried to activate it on the Themes page, the site just returned a blank white page. Even the admin area is just blank.

Then I figured it must have been uploaded to the wrong folder. I went into the CPanel and moved it to themes/AT/templates. Now it appears in the Display Setting > Themes drop down menu. I selected Mobile shop and saved.

When I refreshed my site url, it went blank again.

I just can’t figure it out.

I had to go into the CPanel and delete theme and revert to the default AT theme before things worked again.

Any ideas how to install the child theme? Thanks in advance.