Today, Yahoo announced that its Messenger service will be discontinued after July 17th, 2018. If you’re looking for a Messenger replacement, Yahoo recommends the product Squirrel, which is currently in beta and invite only. You can request an invitation here.
You can download your chat history for the next 6 months at this download request site. Your chats will be emailed to you. If you have anything you want to save from Yahoo Messenger, it’s a good idea to get a copy, because users will be unable to sign into the service after July 17th.