Call to a member function get_the_lifespan() on null
#0 /nas/content/live/questroyal/wp-content/themes/questroyal-child-theme/functions.php(105): qr_post->get_the_artist_lifespan(NULL)
#1 /nas/content/live/questroyal/wp-content/themes/questroyal-child-theme/single.php(12): qr_Helper->__call('get_the_artist_...', Array)
#2 /nas/content/live/questroyal/wp-includes/template-loader.php(74): include('/nas/content/li...')
#3 /nas/content/live/questroyal/wp-blog-header.php(19): require_once('/nas/content/li...')
#4 /nas/content/live/questroyal/index.php(17): require('/nas/content/li...')
#5 {main}