Nostalrius Begins - Quality wow vanilla realm (1.12)

Hi.
I have been playing for around a week with no problem.
But today when I tried to login I get Unable to connect while trying normal mode and Disconnected from server when trying in administration mode.

Is this a known problem that appears after a time?

I've tried every solution in the sticky tread but nothing works, still the same messages when logging in.

What do I do?

Greetings,

As a fast solution, delete WDB and WTF folders, move or delete Addons folder and try to login.
If you try to login on Nostalrius Begins server and still does not work, post your username here and an GM will tell you if the account has been banned or not.