function genesis_activate_fallback_theme( $stylesheet, WP_Theme $old_theme ) { unset( $_GET['activated'] ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended if ( $old_theme->exists() && strpos( $old_theme->get_stylesheet(), 'genesis' ) === false ) { $fallback_stylesheet = $old_theme->get_stylesheet(); } else { $default_theme = WP_Theme::WP_Theme::get_core_default_theme(); $fallback_stylesheet = $default_theme->get_stylesheet(); } switch_theme( $fallback_stylesheet ); }