Why won't Filezilla connect?

Question

FTP

Good day. Help please, I do not know which way to dig. The point is the following.
There is an FTP server on Filezilla in the local network. When you try to connect to it from one of the computers on the network, you get an error 425 can't open data connection for transfer of /. I've tried connecting in both active and passive modes. At the same time, it connects normally from other computers with the same settings, it also connects from the outside, there is no connection from only this one computer. Tried different clients, TC and Filezilla Client, built-in firewall (Windows 10) turned off. I don't know what else to think

Answer 1

The data channel is not opening. FTP is an old and rather complicated protocol. It uses several ports - 20-21 - for transmitting commands and some arbitrary - for data. What port it will be - in FTP transfers either the server to the client (active) or the client to the server (passive).
It is necessary to look in wireshark what goes where, what passes, what does not and why it does not pass.