Notice: Use of undefined constant Redux_TEXT_DOMAIN - assumed 'Redux_TEXT_DOMAIN'

Question

I am building my first Wordpress site, I just downloaded and installed v3.9.1. I bought a theme (rustik3) and I am trying to install it, but I am running into these errors produced by WP_DEBUG:

Notice: Use of undefined constant Redux_TEXT_DOMAIN - assumed 'Redux_TEXT_DOMAIN' in /var/www/wp-content/themes/rustik3/admin/options.php on line 501

Notice: Use of undefined constant Redux_TEXT_DOMAIN - assumed 'Redux_TEXT_DOMAIN' in /var/www/wp-content/themes/rustik3/admin/options.php on line 502

Notice: Use of undefined constant Redux_TEXT_DOMAIN - assumed 'Redux_TEXT_DOMAIN' in /var/www/wp-content/themes/rustik3/admin/options.php on line 503

Notice: Undefined variable: item_info in /var/www/wp-content/themes/rustik3/admin/theme-functions.php on line 23

I have done some googling, and I'm starting to think that the last Wordpress update made it so that the Redux Framework is deprecated and cannot be used. This is just a hunch though. As of right now, the theme installs, but it shows up as completely blank - either when I go to http://localhost or when I am trying to customize it in the Wordpress UI. I haven't looked into the last part of the error messages log (line 23 error)...but it is just an undefined variable so I might be able to tackle that one myself. Any ideas?

UPDATE

This is what the chunk of code looks like in options.php:

array(
            'id' => 'google_webfonts',
            'type' => 'google_webfonts',
            'title' => __('Enable Google Webfonts', Redux_TEXT_DOMAIN), 
            'sub_desc' => __('Pick from over 600 Google Webfonts to use on the site. Then select below which elements you want to apply it to.', Redux_TEXT_DOMAIN),
                'desc' => __('', Redux_TEXT_DOMAIN)
      ),

UPDATE

I did a text search through all of the wordpress files for Redux_TEXT_DOMAIN and the only spot it appears is in the above chunk of code...

UPDATE

This code is what loads the text domain in the theme I have...I am not familiar with what a text domain is - but this might be relevant:

public function load_textdomain() {
        if ( isset( $this->textdomain_loaded ) )
            return $this->textdomain_loaded;

        $textdomain = $this->get('TextDomain');
        if ( ! $textdomain ) {
            $this->textdomain_loaded = false;
            return false;
        }

        if ( is_textdomain_loaded( $textdomain ) ) {
            $this->textdomain_loaded = true;
            return true;
        }

        $path = $this->get_stylesheet_directory();
        if ( $domainpath = $this->get('DomainPath') )
            $path .= $domainpath;
        else
            $path .= '/languages';

        $this->textdomain_loaded = load_theme_textdomain( $textdomain, $path );
        return $this->textdomain_loaded;
    }

Is there something wrong with the above code?

Note: I have posted a duplicate question here. I did this before I was aware that there was a Wordpress specific section of Stack Exchange. If you care about stackoverflow.com - you can answer the question there...I have put a 50 point bounty on it :). You should also read the comments on that page...I think I may have found some relevant information.

UPDATE

Thanks to a comment by cybmeta - I got rid of the Redux_TEXT_DOMAIN errors...the last one left is this:

Notice: Undefined variable: item_info in /var/www/wp-content/themes/rustik3/admin/theme-functions.php on line 23

Here is the code:

$item_info .= '<div class="rustik_updated"><div class="mc_embed_signup_admin">
        <form action="http://doublerainbowx.us6.list-manage2.com/subscribe/post?u=eac2b83a92633c39dae8a663b&amp;id=334c60b856" method="post" id="mc-embedded-subscribe-form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>
            <label for="mce-EMAIL">Get e-mails about important updates and helpful tips on how to run your store by joining the Rustik newsletter.</label>
            <input type="email" value="" name="EMAIL" class="email" id="mce-EMAIL" placeholder="email address" required>
            <!-- real people should not fill this in and expect good things - do not remove this or risk form bot signups-->
            <div style="position: absolute; left: -5000px;"><input type="text" name="b_eac2b83a92633c39dae8a663b_334c60b856" value=""></div>
            <input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button">
            <span><a href="?rustik_updates_nag_ignore=0">Hide Notice</a></span>
        </form>

        </div></div>';

        echo $item_info;

The error is thrown on the echo $item_info line - so it is as if it isn't being set for some reason...even though it looks like it is above.

Answer 1

The problem with your $item_info is that the variable is not initialized before your try to append to it. $item_info .= 'String content'; is the exact same thing as $item_info = $item_info . 'String content';, so all you need is to check whether or not this variable exists:

if (!isset($item_info)) { 
    $item_info = '';
}
$item_info .= '<div class="rustik_updated"><div class="mc_embed_signup_admin">
    <form action="http://doublerainbowx.us6.list-manage2.com/subscribe/post?u=eac2b83a92633c39dae8a663b&amp;id=334c60b856" method="post" id="mc-embedded-subscribe-form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>
        <label for="mce-EMAIL">Get e-mails about important updates and helpful tips on how to run your store by joining the Rustik newsletter.</label>
        <input type="email" value="" name="EMAIL" class="email" id="mce-EMAIL" placeholder="email address" required>
        <!-- real people should not fill this in and expect good things - do not remove this or risk form bot signups-->
        <div style="position: absolute; left: -5000px;"><input type="text" name="b_eac2b83a92633c39dae8a663b_334c60b856" value=""></div>
        <input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button">
        <span><a href="?rustik_updates_nag_ignore=0">Hide Notice</a></span>
    </form>

    </div></div>';

Sometimes developers sell themes/plugins without testing them with warnings ON, that's why you have this error.