Yesterday I could play with my friend. He suddenly couldn't log in to the server at night. I tried his account and I couldn't log in. Then I couldn't log in with my own account.
Keep in mind that sharing accounts is in violation of the rules.
That aside, as I'm unable to translate the error message, I won't be able to give proper advice on it. Are you able to give more details on the error message itself?
Good to hear you're no longer having the issue. The error message itself can occur when the connection between the player and the server is failing. This can indeed be an issue server side, but can also be caused on the player side. (for example bad wifi connection)