Fatal error on network activation (WP Engine)

I get this when activating the plugin on a multisite install on WP Engine (who have their own caching systems):

PHP Fatal error:  Call to undefined function wp_cache_reset() in .../wp-content/plugins/groups/lib/core/class-groups-controller.php on line 46

The error is thrown when the Groups_Controller::switch_to_blog() method tries to call wp_cache_reset():

public static function switch_to_blog( $blog_id ) {
		switch_to_blog( $blog_id );
		if ( function_exists( 'wp_cache_switch_to_blog' ) ) {
			wp_cache_switch_to_blog( $blog_id ); // introduced in WP 3.5.0
		} else {
			wp_cache_reset(); // deprecated in WP 3.5.0
		}
	}

It’s probably safest to check whether wp_cache_reset() exists, just in case it’s actually removed from the core.

https://wordpress.org/plugins/groups/