Problems with X11 Megathread

The following are a list of common problems users have using programs that run using X11.

If you do not see your problem below or a solution does not work, please create a new post on this topic.

X11 window does not open

Common Errors Associated

  • Error: Can't open display
  • java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit (Java)

Common Resolutions

You can use programs like xeyes or xclock at different points in the login process to determine where a problem might be occurring as well.

  • Make sure you SSH to the cluster using the -XY flag. Eg ssh -XY
  • Make sure your srun session uses the --x11 flag. Eg srun --x11 -c 4 --mem 4GB --pty bash -l