For many years I've used ratp.fr to find the Metro route for travel between address. It doesn't work now! Is this temporary? Or, is there a different site i should use? Thanks.
The itinerary planner on RATP.fr doesn't work whenever there's a strike looming, and there is a strike planned for Paris Metro on February 17, 2020.
Try another date, further in the future on their itinerary planner and it should work.