PHP Call to undefined function suddenly

I’ve been using a plugin on WordPress that has been working for months. Suddenly I am seeing this error code:

Fatal error: Call to undefined function sb_get_single_sermon() in /home/drcraigjohnson/public_html/wp-content/plugins/sermon-browser/sermon.php on line 508

I found where this is being called in sermon.php:

/**

* Create the shortcode handler

*

* Standard shortcode handler that inserts the sermonbrowser output into the post/page

*

* @param array $atts

* @param string $content

* @return string

*/

function sb_shortcode($atts, $content=null) {

    global $wpdb, $record_count, $sermon_domain;

    ob_start();

    $atts = shortcode_atts(array(

        'filter' => sb_get_option('filter_type'),

        'filterhide' => sb_get_option('filter_hide'),

        'id' => isset($_REQUEST['sermon_id']) ? $_REQUEST['sermon_id'] : '',

        'preacher' => isset($_REQUEST['preacher']) ? $_REQUEST['preacher'] : '',

        'series' => isset($_REQUEST['series']) ? $_REQUEST['series'] : '',

        'book' => isset($_REQUEST['book']) ? stripslashes($_REQUEST['book']) : '',

        'service' => isset($_REQUEST['service']) ? $_REQUEST['service'] : '',

        'date' => isset($_REQUEST['date']) ? $_REQUEST['date'] : '',

        'enddate' => isset($_REQUEST['enddate']) ? $_REQUEST['enddate'] : '',

        'tag' => isset($_REQUEST['stag']) ? stripslashes($_REQUEST['stag']) : '',

        'title' => isset($_REQUEST['title']) ? stripslashes($_REQUEST['title']) : '',

        'limit' => '0',

        'dir' => isset($_REQUEST['dir']) ? stripslashes($_REQUEST['dir']) : '', ),

    $atts);

    if ($atts['id'] != '') {

        if (strtolower($atts['id']) == 'latest') {

            $atts['id'] = '';

            $wpdb->query('SET SQL_BIG_SELECTS=1');

            $query = $wpdb->get_results(sb_create_multi_sermon_query($atts, array(), 1, 1));

            $atts['id'] = $query[0]->id;

        }

        $sermon = sb_get_single_sermon((int) $atts['id']);

        if ($sermon)

            eval('?>'.sb_get_option('single_output'));

        else {

            echo "<div class="sermon-browser-results"><span class="error">";

            _e ('No sermons found.', $sermon_domain);

            echo "</span></div>";

        }

    } else {

        if (isset($_REQUEST['sortby']))

            $sort_criteria = esc_sql($_REQUEST['sortby']);

        else

            $sort_criteria = 'm.datetime';

        if (!empty($atts['dir']))

            $dir = esc_sql($atts['dir']);

        elseif ($sort_criteria == 'm.datetime')

            $dir = 'desc';

        else

            $dir = 'asc';

        $sort_order = array('by' => $sort_criteria, 'dir' =>  $dir);

        if (isset($_REQUEST['pagenum']))

            $page = $_REQUEST['pagenum'];

        else

            $page = 1;

        $hide_empty = sb_get_option('hide_no_attachments');

        $sermons = sb_get_sermons($atts, $sort_order, $page, (int)$atts['limit'], $hide_empty);

        $output = '?>'.sb_get_option('search_output');

        eval($output);

    }

    $content = ob_get_contents();

    ob_end_clean();

    return $content;

}

It’s being called from a file called frontend.php. Here is that code:

//Gets single sermon from the database
function sb_get_single_sermon($id) {
    global $wpdb;
    $id = (int) $id;
    $sermon = $wpdb->get_row("SELECT m.id, m.title, m.datetime, m.start, m.end, m.description, p.id as pid, p.name as preacher, p.image as image, p.description as preacher_description, s.id as sid, s.name as service FROM {$wpdb->prefix}sb_sermons as m, {$wpdb->prefix}sb_preachers as p, {$wpdb->prefix}sb_services as s where m.preacher_id = p.id and m.service_id = s.id and m.id = {$id}");
    $series = $wpdb->get_row("SELECT ss.id as ssid, ss.name as series FROM {$wpdb->prefix}sb_sermons as m, {$wpdb->prefix}sb_series as ss WHERE m.series_id = ss.id and m.id = {$id}");
    if ($sermon) {
        if ($series) {
            $sermon->series = $series->series;
            $sermon->ssid = $series->ssid;
        }
        else {
            $sermon->series = '';
            $sermon->ssid = 0;
        }
        $file = $code = $tags = array();
        $stuff = $wpdb->get_results("SELECT f.id, f.type, f.name FROM {$wpdb->prefix}sb_stuff as f WHERE sermon_id = $id ORDER BY id desc");
        $rawtags = $wpdb->get_results("SELECT t.name FROM {$wpdb->prefix}sb_sermons_tags as st LEFT JOIN {$wpdb->prefix}sb_tags as t ON st.tag_id = t.id WHERE st.sermon_id = {$sermon->id} ORDER BY t.name asc");
        foreach ($rawtags as $tag) {
            $tags[] = $tag->name;
        }
        foreach ($stuff as $cur)
            ${$cur->type}[] = $cur->name;
        $sermon->start = unserialize($sermon->start);
        $sermon->end = unserialize($sermon->end);
        return array(
            'Sermon' => $sermon,
            'Files' => $file,
            'Code' => $code,
            'Tags' => $tags,
        );
    } else
        return false;
}

I have tried copying / pasting the function directly into admin.php but that breaks because it’s declaring the function twice. So that tells me it’s being called, but not recognized.. I think. Any help is appreciated!