I get a "Cannot open X display" message

Some of you have tried to open SAS, xemacs, or kate from the 'command line', without success. Typical error messages are

ERROR: Cannot open X display. Check display name/server access authorization

ERROR: KUniqueApplication: Can't determine DISPLAY. Aborting.

The only application that launches is emacs, running within your SSH window (in technical terms: in character mode, not GUI mode).

I have tried to typically distinguish between a 'command line' (the shell icon in the taskbar) and the 'SSH prompt', but may have been imperfect in that respect.

SSH prompt:

You log in from your usual workstation (a Windows box, typically), using SSH. When successfully logged in, you are at a command prompt. We will call this the "SSH prompt"

Command line

A shell/terminal window/command line you opened within your VNC session.

There are many ways you can open a command line in your VNC session. Your typical path will be to click the icon in the taskbar.

The difference between the two (for most people) is that within the VNC session at the command line, you have a running X server: thus, if you launch 'sas' from a command line within the VNC window, you will be successful, because the VNC window is an X server. If you do this from your SSH window, you might be successful if you happen to be running an X server on your workstation (Exceed, CygwinX, or a Linux workstation). That being said, even if you did that, performance would probably be slower than if you used the VNC client.