When I want to connect to my server like this
ssh -a username@my-server.de -p 22
it gives me two error messages:
PTY alloca
just found out, what was the problem in my case (provider strato): I had the same problem with output "shell request failed on channel 0" in the end.
I have to use the master password with the web-domain name as login. (In German www.wunschname.de, where wunschname is your web-address.)
A ssh login with sftp-user names and the corresponding passwords is without success. (Although scp and sftp works with these sftp users!)