The First Descendant is available on PlayStation, Xbox, and PC, but you will need to link your platform accounts to the game in order to play. During this process, a pop-up will appear saying “an error has occurred,” confusing players as they attempt to link their account.
The First Descendant: Nexon account linking fixed for console users
When I tried to link my accounts for The First Descendant on Nexon's official page, I received a browser message saying “An error has occurred”.
The "an error has occurred" issue during The First Descendant linking process appears to be a website-related, server-side occurrence. When this error occurs, you are initially returned to the main account linking page. But after waiting for five to ten seconds, the website automatically redirects you to your platform's respective login page.
Once you are on a platform-based login page, simply log in with your account details and let Nexon do the rest. Considering the number of players The First Descendant has, this error could also be related to high traffic.