Intermittent Authentication failed or partial success error - chilkat

Question

I am getting an intermittent Authentication failed or partial success. (1) error.
ChilkatLog:
AuthenticatePw:
DllDate: May 25 2017
ChilkatVersion: 9.5.0.68
UnlockPrefix: XXXXXXXXX
Architecture: Little Endian; 64-bit
Language: .NET 4.5 / x64
VerboseLogging: 0
login: XXXXXXX
sshAuthenticatePw:
requestUserAuthService:
sendServiceRequest:
svcName: ssh-userauth
SentServiceReq: ssh-userauth
--sendServiceRequest
ssh-userauth service accepted.
--requestUserAuthService
AuthMethods: password
passwordAuth:
Sent login/password
Authentication failed or partial success. (1)
PartialSuccess1: 0
AuthList: password
important:
This is likely a simple invalid login and/or password error,
meaning your application did not send the correct login and/or password.
--important
--passwordAuth
--sshAuthenticatePw
Failed.
--AuthenticatePw
--ChilkatLog
What does the (1) in Authentication failed or partial success. (1) mean? Is it the AuthFailReason mentioned here

Answer 1

The LastErrorText is designed to provide information for quick resolution of problems. It contains the information that would likely be needed by the developer to understand the cause of a problem. In our opinion, it is much better than an obscure single-line message or an error code.
It also provides information for Chilkat -- so that if you send us the LastErrorText, we can see context and usually understand the cause of the problem and the solution in one step. Some lines in the LastErrorText might be obscure to the application developer. That's OK, because they are lines meant for us.
In this case the "Authentication failed or partial success. (1)" line is telling Chilkat the execution path that was taken in the internal code. We don't have to guess.
The SSH authentication protocol is such that it's possible for the server to respond with an SSH2_MSG_USERAUTH_FAILURE response, but indicate partial success. In this case, the partial success was 0 (false), so it points to a hard failure -- most likely the simple case that the username and/or password was incorrect.
There is one more possibility, which is somewhat rare. If the server also accepts keyboard-interactive, then you can set Ssh.UncommonOptions = "KeyboardInteractiveFollowup" (or SFtp.UncommonOptions = "KeyboardInteractiveFollowup") to cause Chilkat to retry with a keyboard-interactive request.