FTP Troubleshooting

Running into FTP connection problems? This page covers the most common issues and how to fix them.

Connection Timed Out

Symptoms

Error: Connection timed out after 20 seconds of inactivity
Error: Could not connect to server

Solutions

• Check the hostname. Make sure you are using ftp.yourdomain.com or your server's IP address. Typos in the hostname are a common cause.
• Check the port. Use port 21 for standard FTP/FTPS. Port 990 is only for implicit FTPS.
• Check your firewall. Your local firewall, antivirus, or router may be blocking outgoing FTP connections. Temporarily disable your firewall to test, and if that fixes it, add an exception for your FTP client.
• Try a different network. Some corporate or public Wi-Fi networks block FTP traffic. Try connecting from a different network or use a mobile hotspot to test.
• Increase the timeout value. In FileZilla, go to Edit → Settings → Connection and increase the timeout to 30-60 seconds.

530 Login Incorrect

Symptoms

Response: 530 Login incorrect.
Error: Critical error: Could not connect to server

Solutions

• Use the full username. FTP usernames include your domain. For example, if you created an FTP account called uploads, the full username is uploads@yourdomain.com.
• Check for typos. Passwords are case-sensitive. Copy and paste your password directly to avoid mistakes. Watch out for trailing spaces.
• Reset the password. Log into cPanel, go to FTP Accounts, and click Change Password next to the account. Set a new password and try again.
• Check if the account exists. Verify the FTP account is listed in cPanel under FTP Accounts. It may have been deleted.
• cPanel credentials. If you are logging in with your main cPanel username (not the full email-style format), make sure the password matches your current cPanel password.

Passive Mode Errors

Symptoms

Error: Failed to retrieve directory listing
Response: 227 Entering Passive Mode
Error: Connection timed out

You connect successfully but cannot browse folders or transfer files.

Solutions

• Ensure passive mode is enabled. In FileZilla, go to Edit → Settings → Transfers → FTP: Transfer Mode and select Passive. Active mode rarely works behind NAT routers or firewalls.
• Check your firewall. Passive mode requires your FTP client to accept incoming data connections on random high ports. Make sure your firewall allows your FTP client full network access.
• Limit simultaneous connections. Set maximum simultaneous transfers to 2 in your FTP client settings. Too many connections can trigger server-side limits.

TLS/SSL Certificate Errors

Symptoms

Error: The server's certificate is unknown. Trust this certificate?
Error: GnuTLS error -15: An unexpected TLS packet was received
Error: Could not connect to server - TLS connection failed

Solutions

• Accept the certificate. On first connection, your FTP client will ask you to verify the server's TLS certificate. This is expected. Check "Always trust this certificate" and continue.
• Check your encryption setting. Make sure you are using the correct encryption type for your port:
  • Port 21: Use Explicit FTP over TLS
  • Port 990: Use Implicit FTP over TLS
• Try a different encryption mode. If "Require explicit FTP over TLS" fails, try "Use explicit FTP over TLS if available" to see if that resolves the issue.
• Update your FTP client. Older versions of FileZilla and other clients may have TLS compatibility issues. Download the latest version from the official website.
• Clear the certificate cache. In FileZilla, go to Edit → Settings → FTP and click Clear certificate cache, then reconnect.

Transfer Failures and Broken Uploads

Symptoms

Error: Transfer connection interrupted
Error: File transfer failed after transferring X bytes
Error: 421 Too many connections from your IP

Solutions

• Reduce simultaneous transfers. Set the maximum to 2 in your client settings. Shared hosting limits the number of concurrent FTP connections per account.
• Check your disk quota. If your hosting account is out of disk space, uploads will fail. Check usage in cPanel under Disk Usage.
• Upload smaller batches. If you are uploading hundreds of files, break them into smaller groups. Consider zipping large sets and extracting them via cPanel's File Manager instead.
• Check file permissions. If you get "permission denied" errors, the target directory may not be writable. Check permissions in cPanel's File Manager (directories should be 755, files 644).

Connection Drops After Being Idle

Symptoms

You are connected and working, but after a few minutes of inactivity the connection drops.

Solutions

• Enable keepalive. In FileZilla, go to Edit → Settings → FTP and check Send FTP keep-alive commands. This sends periodic signals to prevent the server from closing idle connections.
• Reconnect automatically. FileZilla will attempt to reconnect when you perform an action after a disconnection. Simply resume your work and it will re-establish the connection.

Still Having Problems?

If none of the above solutions work, contact our support team through the Client Area. When submitting a ticket, include:

• Your domain name
• The FTP username you are using
• Your FTP client name and version
• The full error message from the connection log
• Your public IP address (you can find this at tools.ultrawebhosting.com)