FTP client stopped working on win 8.1, where to dig?

Question

FTP

Good afternoon.
Everything was great everything worked.
At one point, filezilla stopped connecting. Other ftp clients don't work either.
The Internet goes through the server, other users connect, from the server itself, too, all the rules.
Node 32 is installed on my wheelbarrow, it does not block ports, the firewall is cut down. I read that bounjour can interfere with work, I also cut it out, the result is the same, there is no connection to FTP.
Here is what FTP clients give out:

Статус:	Соединяюсь с х.х.х.х:21...
Ошибка:	Соединение прервано после 20 секунд неактивности
Ошибка:	Невозможно подключиться к серверу

where to dig?
thanks in advance.

Answer 1

VanKLiF , telnet doesn't work either =(
In general, everything worked, rebooted the server and everything worked, xs because of what it was, ports are registered in the firewall on the server, both input and output traffic.

Answer 2

First, try to tap the port with Telnet .... And then look further