php - Cannot modify header information - headers already sent by... WordPress Issue

I'm encountering this error. and I have no idea dealing with
this.

Cannot modify header information - headers already sent by (output

started at

/home/ben213/public_html/wp-content/themes/Bendaggers/functions.php:9)
in
/home/ben213/public_html/wp-includes/pluggable.php on line
934

my
Functions.php file line # 9
is:

            if(function_exists('register_sidebar'))register_sidebar();?>

while
my pluggable.php # 934
is

function
            wp_redirect($location, $status = 302) {
 global $is_IIS;


            $location = apply_filters('wp_redirect', $location, $status);
 $status =
            apply_filters('wp_redirect_status', $status,
            $location);


 if ( !$location ) // allows the wp_redirect
            filter to cancel a redirect
 return false;

 $location =
            wp_sanitize_redirect($location);

 if ( !$is_IIS &&
            php_sapi_name() != 'cgi-fcgi' )
 status_header($status); // This causes
            problems on IIS and some FastCGI setups

 header("Location:
            $location", true,
            $status);}
endif;

I'm
having a hard time figuring this out since im not a programmer. what seems to be
wrong?
kindly help me please...

class="post-text" itemprop="text">

class="normal">Answer

Your theme
is printing output (text) to the browser, but then for some reason WordPress is
redirecting the user (with wp_redirect) away from that page before the whole page is
rendered. You can't start printing output and then redirect, or you'll get the error you
see. That's what Paul Grime was getting at in his comment.

Ken White commented with a reference to a post
with a similar problem. I've fixed this in my own experience by buffering the output of
the script.

In your theme's
functions.php file (which gets included every time your theme's
pages load), put the
following:

//allow
            redirection, even if my theme starts to send output to the
            browser
add_action('init', 'do_output_buffer');
function
            do_output_buffer() {

            ob_start();
}

Now,
even if part of your theme starts to send input to the browser, PHP won't send that text
until the page is fully loaded, which allows WordPress to redirect users, if necessary,
as part of its own logic.