When Fortnite cannot sign in to the Epic account, the game stops before the lobby, usually with an unable to sign in message. The cause is most often the login itself, an Epic service problem, or the launcher's cached sign-in data, and each one has a different fix.
If the website signs in fine but the launcher still refuses, reinstall the Epic Games Launcher, since a corrupted launcher can fail sign-in while the account itself is healthy. If the website also refuses and no password reset email arrives, check the spam folder, and contact Epic Support, since the account may be locked or the email on file may be wrong.
Why can I sign in on the website but not in Fortnite? The launcher keeps its own cached sign-in data, and a corrupted cache or a stale session can fail while the account itself is fine. Clearing the web cache or signing out and back in normally fixes it.
Does unable to sign in mean my account is banned? Not usually. A banned account shows a clear notice when signing in on the website. A plain sign-in failure is more often a wrong password, a service outage, or a launcher problem.
I never get the password reset email, what now? Check the spam folder first, then confirm the email address on the account is one you can still open. If the email on file is an old address you no longer use, only Epic Support can change it.