En la página de Elder Scrolls sale lo siguiente:
"Due to unforeseen issues, the Homestead update on the European megaserver will be delayed for at least five hours. We apologize for the inconvenience.
While the delay is ongoing, you will receive an error stating "You've attempted to use an invalid or out-dated client" when trying to log into the European megaserver, even if you have downloaded the correct update in the ESO Launcher."
Está publicado a las 10 de la mañana, así que espero no tarden mucho. Supongo que solo nos queda tener paciencia,