2. If you see 530 Login authentication failed lik ethis one:
Command: PASS ************
Response: 530 Login authentication failed
Error: Critical error: Could not connect to server
Make sure you have entered correct host name and password.
2. If you receive timeout message:
Error: Connection timed out after 20 seconds of inactivity
Error: Failed to retrieve directory listing
Make sure you enter the correct host name, port number, Encryption settings, username and password.
3. Also make sure your firewall doesn’t block the FTP traffic.
Please refer to this link for how to configure FTP client: How to configure FTP client