Blank page when updating WordPress Site

I’m receiving a blank page when updating page/posts/and even logging in. I’ve isolated the problem and have found that it has to do with my theme.

Here is the problem I’m having:

PHP Warning: Cannot modify header information - headers already sent by (output started at /home2/homecare/public_html/wp-content/themes/silvertree/functions.php:1433) in /home2/homecare/public_html/this is where the problem pertains to the page that isn’t loading.

The thing is, line 1433 in my functions.php file is the very end of the document, so I’m not sure where to find the problem or what it is I’m supposed to fix. Any help will be appreciated.