Can you authenticate using any other SSH/SFTP client? If not, the problem must be on their end. If you can, please post logs both from WinSCP and the other client.

Hi,

I'm getting the attached error box when trying to retrieve data sent to me from my vendor I've used previously. Their engineers are saying they have used the public key I've sent to submit the data and everything looks great on there end, and there is nothing else they can do. I'm entering the correct private key password. Any ideas?