white page after activating new theme

When I choose another theme (not true of all themes but this one in particular as far as I know) I get the white page on my blog AND in the admin. Some of the themes show white when using the preview in the themes area as well.

Now when I go to admin and try anything, all areas are white. I did manage to hit the BACK button to where I was before to choose a theme and it shows and I try to select another theme but still no dice on anything.

Any ideas what would make this happen and how to change it? My site is https://www.pampermeplace.net