White Screen upon installation

Hey,

So I just bought the theme off of Themeforest.

Uploaded the “oblivion” folder via Filezilla onto WordPress.

Once I click on “Activate” under the theme section of WordPress my entire screen goes white and doesn’t allow me to do anything anymore.
This includes looking at my site, access my WordPress Dashboard, etc.

This is my site: http://www.5tefanK.com

Would appreciate any help as I am seriously confused.

Thanks!