wordpress is trying to open my index.php file

Please explain what do you mean by opening your index.php, are you saying that you are seeing the actual PHP code, ie., you see:

<?php
/**
 * Front to the WordPress application. This file doesn't do anything, but loads
 * wp-blog-header.php which does and tells WordPress to load the theme.
 *
 * @package WordPress
 */

/**
 * Tells WordPress to load the WordPress theme and output it.
 *
 * @var bool
 */
define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require('./wp-blog-header.php');

Thanks Max. Not really, it’s trying to download the index.php file rather than having it launch my website.

I haven’t touched the site recently and sucuri says it’s fine. I had backupbuddy running on it, but I wouldn’t think that would do anything either. I’ve never seen this before.

I looked at the .htaccess file and it was missing the code in between:
# BEGIN WordPress
# END WordPress

I added in the regular code that is supposed to go there, but it didn’t help. It’s on a windows server so not even sure if it’s reading .htacess…

Usually when you have a .php file downloading or the contents displaying it means that your PHP interpreter is not getting called, so the php handler is miss-configured.

Since you are still talking about .htaccess, I assume you are running Apache on windows. Do you know if you are using mod_php or are you calling php as a CGI script with something like mod_fcgi?

Are these sites all on the same server? If so, I’d bet the PHP interpreter is failing. This is a SERIOUS PROBLEM, since it means your wp-config.php file can be downloaded in plaintext. Contact your host immediately (and change all your credentials once it gets fixed).

Have you tried a different computer?