534-Protection level negotiation failed


2016-11-16 13:19:30 UTC


2017-04-24 11:21:22 UTC


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534-Protection level negotiation failed

Applicable to:

  • Plesk 11.5 for Windows
  • Plesk 12.0 for Windows


Cannot connect to FTP server, the following error is shown:

Command:    LIST
Response: 534-Protection level negotiation failed.
Response: Win32 error: Access is denied.
Response: Error details: Protection negotiation failed. PROT command with recognized parameter must precede this command.
Response: 534 End
Error: Failed to retrieve directory listing


FTP client expects the certificate or secure connection.


Enable "Allow both secure FTPS and non-secure FTP connections" option for the IP address under Plesk -> Tools & Settings -> IP Addresses -> .

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