PHP error: CATCHABLE FATAL ERROR:

I have trouble with theme Archi, on page

https://www.sadarch.sk/o-nas/o-nas-2/

this error

DOMOV /
CATCHABLE FATAL ERROR: OBJECT OF CLASS WP_ERROR COULD NOT BE CONVERTED TO STRING IN /HOME/OA004100/SADARCH_SK/WP-CONTENT/THEMES/ARCHI/FUNCTIONS.PHP ON LINE 486

line 486 – sadarch_sk/wp-content/themes/archi/functions.php:

$cats = str_replace('<a', $linkBefore . '<a' . $linkAttr, $cats);

Whole function code:

function archi_breadcrumbs() {
    $text['home']     = __('Home', 'archi'); // text for the 'Home' link
    $text['category'] = '%s'; // text for a category page
    $text['tax']      = '%s'; // text for a taxonomy page
    $text['search']   = '%s'; // text for a search results page
    $text['tag']      = '%s'; // text for a tag page
    $text['author']   = '%s'; // text for an author page
    $text['404']      = '404'; // text for the 404 page
    $showCurrent = 1; // 1 - show current post/page title in breadcrumbs, 0 - don't show
    $showOnHome  = 0; // 1 - show breadcrumbs on the homepage, 0 - don't show
    $delimiter   = ' <b>/</b> '; // delimiter between crumbs
    $before      = '<li class="active">'; // tag before the current crumb
    $after       = '</li>'; // tag after the current crumb
    
    global $post;
    $homeLink = esc_url(home_url('/')) . '';
    $linkBefore = '<li>';
    $linkAfter = '</li>';
    $linkAttr = ' rel="v:url" property="v:title"';
    $link = $linkBefore . '<a' . $linkAttr . ' href="%1$s">%2$s</a>' . $linkAfter;
 
    if (is_home() || is_front_page()) {
 
        if ($showOnHome == 1) echo '<div id="crumbs"><a href="' . $homeLink . '">' . $text['home'] . '</a></div>';
 
    } else {
 
        echo '<ul class="crumb">' . sprintf($link, $homeLink, $text['home']) . $delimiter;
 
        
        if ( is_category() ) {
            $thisCat = get_category(get_query_var('cat'), false);
            if ($thisCat->parent != 0) {
                $cats = get_category_parents($thisCat->parent, TRUE, $delimiter);
                $cats = str_replace('<a', $linkBefore . '<a' . $linkAttr, $cats);
                $cats = str_replace('</a>', '</a>' . $linkAfter, $cats);
                echo htmlspecialchars_decode( $cats );
            }
            echo htmlspecialchars_decode( $before ) . sprintf($text['category'], single_cat_title('', false)) . htmlspecialchars_decode( $after );
 
        } elseif( is_tax() ){
            $thisCat = get_category(get_query_var('cat'), false);
            if ($thisCat->parent != 0) {
                $cats = get_category_parents($thisCat->parent, TRUE, $delimiter);
                $cats = str_replace('<a', $linkBefore . '<a' . $linkAttr, $cats);
                $cats = str_replace('</a>', '</a>' . $linkAfter, $cats);
                echo htmlspecialchars_decode( $cats );
            }
            echo htmlspecialchars_decode( $before ) . sprintf($text['tax'], single_cat_title('', false)) . htmlspecialchars_decode( $after );
        
        }elseif ( is_search() ) {
            echo htmlspecialchars_decode( $before ) . sprintf($text['search'], get_search_query()) . htmlspecialchars_decode( $after );
 
        } elseif ( is_day() ) {
            echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
            echo sprintf($link, get_month_link(get_the_time('Y'),get_the_time('m')), get_the_time('F')) . $delimiter;
            echo htmlspecialchars_decode( $before ) . get_the_time('d') . htmlspecialchars_decode( $after );
 
        } elseif ( is_month() ) {
            echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
            echo htmlspecialchars_decode( $before ) . get_the_time('F') . htmlspecialchars_decode( $after );
 
        } elseif ( is_year() ) {
            echo htmlspecialchars_decode( $before ) . get_the_time('Y') . htmlspecialchars_decode( $after );
 
        } elseif ( is_single() && !is_attachment() ) {
            if ( get_post_type() != 'post' ) {
                $post_type = get_post_type_object(get_post_type());
                $slug = $post_type->rewrite;                
                if ( get_post_type() == 'portfolio' ) {
                    printf($link, $homeLink . '' . $slug['slug'] . '/', 'portfolio'); //Translate portfolio breadcrumb.
                }elseif (get_post_type() == 'service') {
                    printf($link, $homeLink . '' . $slug['slug'] . '/', 'service'); //Translate service breadcrumb.
                }else{
                    printf($link, $homeLink . '' . $slug['slug'] . '/', $post_type->labels->singular_name);
                }
                if ($showCurrent == 1) echo htmlspecialchars_decode( $delimiter ) . $before . get_the_title() . $after;
            } else {
                $cat = get_the_category(); $cat = $cat[0];
                $cats = get_category_parents($cat, TRUE, $delimiter);
                if ($showCurrent == 0) $cats = preg_replace("#^(.+)$delimiter$#", "$1", $cats);
                $cats = str_replace('<a', $linkBefore . '<a' . $linkAttr, $cats);
                $cats = str_replace('</a>', '</a>' . $linkAfter, $cats);
                echo htmlspecialchars_decode( $cats );
                if ($showCurrent == 1) echo htmlspecialchars_decode( $before ) . get_the_title() . $after;
            }
 
        } elseif ( !is_single() && !is_page() && get_post_type() != 'post' && !is_404() ) {
            $post_type = get_post_type_object(get_post_type());
            echo htmlspecialchars_decode( $before ) . $post_type->labels->singular_name . htmlspecialchars_decode( $after );
 
        } elseif ( is_attachment() ) {
            $parent = get_post($post->post_parent);
            $cat = get_the_category($parent->ID); $cat = $cat[0];
            $cats = get_category_parents($cat, TRUE, $delimiter);
            $cats = str_replace('<a', $linkBefore . '<a' . $linkAttr, $cats);
            $cats = str_replace('</a>', '</a>' . $linkAfter, $cats);
            echo htmlspecialchars_decode( $cats );
            printf($link, get_permalink($parent), $parent->post_title);
            if ($showCurrent == 1) echo htmlspecialchars_decode( $delimiter ) . $before . get_the_title() . $after;
 
        } elseif ( is_page() && !$post->post_parent ) {
            if ($showCurrent == 1) echo htmlspecialchars_decode( $before ) . get_the_title() . $after;
 
        } elseif ( is_page() && $post->post_parent ) {
            $parent_id  = $post->post_parent;
            $breadcrumbs = array();
            while ($parent_id) {
                $page = get_page($parent_id);
                $breadcrumbs[] = sprintf($link, get_permalink($page->ID), get_the_title($page->ID));
                $parent_id  = $page->post_parent;
            }
            $breadcrumbs = array_reverse($breadcrumbs);
            for ($i = 0; $i < count($breadcrumbs); $i++) {
                echo htmlspecialchars_decode( $breadcrumbs[$i] );
                if ($i != count($breadcrumbs)-1) echo htmlspecialchars_decode( $delimiter );
            }
            if ($showCurrent == 1) echo htmlspecialchars_decode( $delimiter ) . $before . get_the_title() . $after;
 
        } elseif ( is_tag() ) {
            echo htmlspecialchars_decode( $before ) . sprintf($text['tag'], single_tag_title('', false)) . $after;
 
        } elseif ( is_author() ) {
             global $author;
            $userdata = get_userdata($author);
            echo htmlspecialchars_decode( $before ) . sprintf($text['author'], $userdata->display_name) . $after;
 
        } elseif ( is_404() ) {
            echo htmlspecialchars_decode( $before ) . $text['404'] . $after;
        }
 
        if ( get_query_var('paged') ) {
            if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() );
            if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ')';
        }
 
        echo '</ul>';
 
    }
}

Archi theme
https://themeforest.net/item/archi-interior-design-wordpress-theme/12649286?_ga=2.18347513.1136331151.1519657789-204806849.1519657789

Ocean Themes

https://themeforest.net/user/oceanthemes

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