Update broke site

Fatal error: Call to undefined function nf_is_func_disabled() in /home/content/a2pnexwpnas01_data01/86/3551486/html/wp-content/plugins/ninja-forms/deprecated/includes/admin/upgrades/class-upgrade-handler.php on line 32

I’ve tried to troubleshoot this issue and even manually updated Ninja but the only solution is to disable the plugin completely. Any suggestions?