Fatal error: Call to undefined function pmpro_https_filter() in /home/wholondo/public_html/wp-content/plugins/pmpro-register-helper-master/pmpro-register-helper.php on line 177
Do you have a copy of the plugin? I mean, the previous version.
It is safe to assume that if it happened right after the upgrade, the plugin is at fault…And for the path, it is… Plugins in WP can be installed by simply copying the files where they should go so maybe you can go back to the previous version