Git SCM does not correctly encode the username if it is a local user to a Windows machine because it contains a "+".

The job's SCM configuration page connects successfully with a username containing a "+", but the Git Polling Log uses the incorrectly encoded username.

I have verified on the Windows logs that the sshd login was rejected because the username had a "%252b" instead of a "+".

SSH credential is Globally scoped, does not have a paraphrase, and is using a private ssh-rsa key located on Jenkins master. The credential does NOT use the "MACHINE+user" format. It just has "uniqueUser". This same credential is used successfully to SSH into Linux slaves. The Master node Windows SSH server utilizes a common login "MACHINE+user", and validates "uniqueUser" based on a uniqueUser.pub key.