Fortnite's new patch dropped today, but it looks as though fans are struggling to board the Battle Bus and get playing.
A new "That Wasn't Supposed To Happen" error is preventing players from logging in.
Fortnite Down: How To Fix "Battle Buses Are Full" Error Code
Check out the screenshot below, with the error code "match.session_unavailable.402".
Luckily, it seems the issue is easy to fix - just make sure your game is updated.
Here's how to do that on all platforms:
Quit Fortnite, and if an update is available, it'll be downloaded via the Epic Games Store.
On Sony consoles, head to your dashboard and highlight Fortnite.
Press the options button, and then "Check for update".
Xbox One/Series S/Series X
On Xbox, head into "My Games and Apps".
From there, check the "Updates" section on the left, and ensure if Fortnite appears that you install it.