failed to open stream:

Hi,
I am very new to all this and when istalling the theme I getthe following – what do I need to do?
:-

Installing Theme from uploaded file: exposure.zip

Unpacking the package…

Installing the theme…

Theme installed successfully.

Warning: fopen(/home/hookline/public_html/wp-content/themes/exposure/style.css) [function.fopen]: failed to open stream: No such file or directory in /home/hookline/public_html/wp-includes/functions.php on line 4339

Warning: fread() expects parameter 1 to be resource, boolean given in /home/hookline/public_html/wp-includes/functions.php on line 4342

Warning: fclose() expects parameter 1 to be resource, boolean given in /home/hookline/public_html/wp-includes/functions.php on line 4345