It appears that the Fortnite servers have gone down, so you might be receiving an error when trying to login. You aren't alone if this is happening, a whole lot of players are experiencing it, and Epic is aware of the issues and is working on them. We aren't sure how long it will be until it is fixed, so you might just need to look elsewhere for entertainment for the time being!
The Fortnite Status Twitter tweeted the following information when the issue started:
We're investigating issues related to kicks and logins. We'll provide an update when these are resolved.
If you are receiving the message" Your account no longer has play access to Fortnite" then don't worry! You are not banned and you did not lose all of your cosmetics or account. This is merely a message players are receiving that goes along with the "You do not have permission to play Fortnite" error. Both of these just mean that you can't access the game right now because the servers are down. This was also tweeted out by the Fortnite Status Twitter:
Players who see a message saying "You do not have permission to play Fortnite" or "Your account no longer has play access to Fortnite" because of this issue are not banned from Fortnite.
Never fear Fortnite players! Epic is on the case and the servers should be back up eventually. Unfortunately, there's nothing you can really do to fix the issue and you will just need to wait until it gets resolved. Epic surely does not want you to not have access to the game, so they are very likely making it their highest priority to get Fortnite back to a functioning state as soon as possible!