Non-Manifesto exception

Error: Call to a member function get_fullname() on null in /xvar/www/html/socialanarchism.org/site/mods/magazine/classes/MagazineArticle.php:468 Stack trace: #0 /xvar/www/html/socialanarchism.org/site/mods/magazine/classes/MagazineArticle.php(343): dadaTypo\Modules\Magazine\MagazineArticle->get_author() #1 /xvar/www/html/socialanarchism.org/site/mods/magazine/controller.inc(45): dadaTypo\Modules\Magazine\MagazineArticle->display() #2 /xvar/www/html/socialanarchism.org/site/themes/sociala/page_layouts/module.tmpl.php(165): include('/xvar/www/html/...') #3 /xvar/www/html/socialanarchism.org/site/mods/magazine/module_prep.inc(70): require('/xvar/www/html/...') #4 /xvar/www/html/socialanarchism.org/index.php(113): include('/xvar/www/html/...') #5 {main}