Troubleshooting Center

Read the message log

FileZilla’s upper pane is the message log. The status bar only says that something failed. The log says which command was sent and which response came back. Open a saved site from File → Site Manager rather than retyping the quick-connect bar, so the protocol and port stay visible.

Ignore the pile of automatic retries until you have marked the first error. A timeout that is followed by “Critical error: Could not connect to server” is still a timeout.

Order of checks

1. Did a TCP connection open? A refusal or a timeout stops the session before a password exists in the exchange.
2. What greeted you? 220 means an FTP service. A line starting with SSH-2.0 means SSH. A TLS error before either greeting means the encryption mode does not match the port.
3. Did authentication finish? 230 on FTP or FTPS, or a completed SSH login, means the account was accepted.
4. Did the file list fail after that? On FTP and FTPS, inspect the data connection. On SFTP, inspect the remote path and permissions.

Symptom map

• ECONNREFUSED or ETIMEDOUT The socket never became a session. Use connection errors and confirm the port in setup.
• 530, or “Authentication failed” The service answered and rejected the method. Use authentication issues.
• Failed to retrieve directory listing, 425, or 227 Login already worked. Use directory listing problems.
• Certificate dialog, GnuTLS error, or SSH host key The identity check failed or has not been verified. Use secure file transfers.
• 421 Too many connections The server accepted the address and then applied a limit. Lower simultaneous transfers, or wait, instead of changing the password.

Run the diagnostic

The tool below repeats this sorting in shorter form. It does not replace the guides, and it does not test a hostname.

If you write to Filenilla

Copy the protocol, the port, and the first failed status or response line. Stop before any line that would contain a password. FileZilla masks PASS in the log; do not reconstruct it in the email. Send that to the contact form or to [email protected]. Filenilla does not sign in to customer servers, and a reply is not guaranteed.