Ben Leonard (Customer) asked a question.

October 7, 2026 at 12:38 PM
WS_FTP Pro no longer accepting password protected SSH keys after 13.0 update.

Since upgrading to WS_FTP Pro 13.0/13.0.1, I am no longer able to import password-protected SSH private keys. When selecting the private key during the import process, WS_FTP displays the error:

 

"Unsupported File Format"

 

The same key pair imports successfully into WS_FTP Pro 12.x without any issues. As a workaround, I have been able to copy the following directory from a system running the older version:

 

C:\Users\<new_profile>\AppData\Roaming\Ipswitch\WS_FTP\SSH\

 

After copying the SSH configuration files, the keys work correctly in the newer version.

 

I have tested key pairs generated with both PuTTY and OpenSSH. The keys were created using RSA 4096-bit encryption, including PPK version 2 and PPK version 3 formats. In all cases, password-protected keys fail to import into WS_FTP Pro 13.x, while non-password-protected keys import successfully.

  • 1 answer
  • 31 views

  • Samik Chakraborty (Progress Software Development)

    @Ben Leonard (Customer)​  Hi Ben, We are aware of this issue. Would appreciate if you can raise a ticket with Progress technical support so that we can share more information.