Server Unexpectedly Closed connection

I am getting this error on a server and I can't figure out why. I was able to connect one time upon first install then all subsequent tries fail with the same error. The error message comes up while trying to connect. I am able to connect from my laptop with the exact same settings. I am also unable to connect using C#...it gives the same error. Help is appreciated. Log file is attached.

I have read through several other support requests on this subject and none have helped me solve it.

Can you connect with any other SFTP/SSH client?

Yes I can. I was able to connect once with WinSCP then it started with this error. I caught the error in my C# code and what it is saying is the SSH key is not formatted correctly even though I took it directly from the generated code within the client.

So what client? Can you post its verbose log file, when running on the same machine as WinSCP?