Symptoms
- Cannot connect to FTP server using FileZilla:
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 - Connections using other FTP client software and from Plesk server itself are possible.
Cause
FTP client expects the certificate or secure connection, but FTP server does not offer it.
Resolution
Note: if you don’t have Plesk administrator credentials, contact your hosting provider regarding the issue
Allow secure and non-secure FTP connections in Plesk:
for all websites
- Log in to Plesk as admin
- Go to Tools & Settings > Security policy > Secure FTP and select Allow both secure FTPS and non-secure FTP connections:
for all websites on particular Plesk IP address (on Windows only)
- Determine IP address of the websites, for example:
# ping example.com
- Log in to Plesk as admin
- Go to Tools & Settings > Security policy > Secure FTP and select Use custom FTPS policy per IP address:Â
- Go to Tools & Settings > IP addresses > ip_address and select Allow both secure FTPS and non-secure FTP connections:
