Notice: Trying to get property ‘term_id’ of non-object in wp-content [closed]

I receive the error on my homepage as follows.
Notice: Trying to get property ‘term_id’ of non-object in /var/www/web17/htdocs/paladise.de/wp-content/themes/sohopro/vc_templates/gt3_portfolio_grid.php on line 46

if (is_array($categ_array) && count($categ_array) > 0) {
    foreach ($categ_array as $cat) {
        $this_categ = get_term_by('slug', $cat, 'portcat');
        $this_categ_id = $this_categ->term_id;
        array_push($filter_categ_array, $this_categ_id);
    }
}

So, How to fix it? Thanks