When you run into this error for an SFTP connection: Error: Received unexpected end-of-file from SFTP server
A needed configuration change in the sshd_config file to allow this connection to work.
Edit the sshd_config file in /etc/ssh/ with your favorite editor, save the file, and restart ssh.
Once in the sshd_config file, scroll down until you see this line:
# Subsystem sftp /usr/lib/openssh/sftp-server
Make sure that above line is commented out if it isn't already. Then, add the below line to the configuration.
Subsystem sftp internal-sftp
Now, save this file and restart ssh to make it take effect.