Hundreds of people have complained they are unable to play popular video game Fortnite.
A mystery outage was reported this afternoon, with users saying they could not access the game online.
Frustrated fans were met with messages saying "Invalid Client" as they tried to access the game.
It is understood to be an issue with the Epic Games Store, with other popular titles including Rocket League affected.
It is not clear why people were unable to play, but a large volume of gamers reported the outage to website Down Detector, which monitors connection issues.
Earlier today Fortnite's official Twitter account retweeted a post that said: "We are investigating issues where logging into Epic Games accounts fails with the "Invalid Client" error and preventing from logging in to the game. We will update you when this issue is resolved."
Around 4.10pm the Epic Games Status website was updated to say: "We are continuing to work on a fix for this issue."
The official Epic Games Twitter account posted: "We're aware of an issue with logging into Epic Games accounts.
"We will update you when this issue is resolved."
The official Epic Games Status website was also updated with info on the 'authentication' issues hitting players.
Around 1.30pm UK time today the Epic Games Status website was updated to say: "Players are currently unable to log in to their Epic Games account, Epic Online Services and connecting to games."
