Here is a table of some of the most frequent errors that you may encounter while using FTP clients:
| Error Code | Error Message | Description |
|---|---|---|
| 421 | Service not available, closing control connection | The FTP server is busy and cannot accept any more connections. Try again later. |
| 425 | Can't open data connection | The FTP client was not able to establish a data connection to the server. This may be due to a firewall or other network configuration issue. |
| 530 | Login authentication failed | The FTP client was not able to authenticate with the server using the provided username and password. Check that the credentials are correct and that the account is active. |
| 550 | Permission denied | The FTP client was not able to access the requested file or directory on the server. This may be due to incorrect permissions, or the file or directory may not exist. |
| 553 | Could not create file | The FTP client was not able to create the requested file on the server. This may be due to incorrect permissions or disk space issues on the server. |
| 226 | Transfer complete | The FTP client successfully transferred the requested file to or from the server. |
| 421 | Timeout detected | The FTP client timed out while waiting for a response from the server. This may be due to network connectivity issues or a problem with the server. |
| 550 | File not found | The FTP client was not able to find the requested file on the server. Check that the file exists and that the path is correct. |
| 425 | Unable to build data connection | The FTP client was not able to establish a data connection with the server. This may be due to a network configuration issue or a problem with the server. |
