In Windows XP Professional create a new user account and create a password for it.
Then try to log in using sftp and the session will hang just after entering the password.
| Exception in thread "SubsystemServer 5" java.lang.NullPointerException
INFO | jvm 1 | 2007/03/28 19:53:09 | at com.sshtools.j2ssh.sftp.VirtualFileSystem.translateNFSPath(Unknown Source)
INFO | jvm 1 | 2007/03/28 19:53:09 | at com.sshtools.j2ssh.sftp.SftpSubsystemServer.onRealPath(Unknown Source)
INFO | jvm 1 | 2007/03/28 19:53:09 | at com.sshtools.j2ssh.sftp.SftpSubsystemServer.onMessageReceived(Unknown Source)
INFO | jvm 1 | 2007/03/28 19:53:09 | at com.sshtools.j2ssh.subsystem.SubsystemServer.run(Unknown Source)
INFO | jvm 1 | 2007/03/28 19:53:09 | at java.lang.Thread.run(Unknown Source)
DEBUG | wrapperp | 2007/03/28 19:53:0
This happens even if before trying to connect by sftp you create the user's profile/home directory.
Instead, if you logged in windows graphically at least once, the home directory is populated with some system files and the daemon works correctly.