Why Don't Some Themes Install; "Warning:"!

Hi I have noticed that several themes I have tried to install have resulted in a message similar to this (this is the latest one but they all look similar to this):

Warning: fopen(/home/content/x/r/o/xroox/html/drewclifton.com/wp-content/themes/Theme Files/style.css) [function.fopen]: failed to open stream: No such file or directory in /home/content/x/r/o/xroox/html/drewclifton.com/wp-includes/functions.php on line 4165

Warning: fread(): supplied argument is not a valid stream resource in /home/content/x/r/o/xroox/html/drewclifton.com/wp-includes/functions.php on line 4168

Warning: fclose(): supplied argument is not a valid stream resource in /home/content/x/r/o/xroox/html/drewclifton.com/wp-includes/functions.php on line 4171

What is this all about? How can I avoid this? Please advise I don’t know what to do, this happens every time I find a theme I like (practically) lately.

EDIT: I see now there are some advanced installation instructions for this theme which I will read and try, then report what happened! Whoops 🙂