From: John Stone (
Date: Wed Feb 05 2020 - 15:04:07 CST

  This isn't really an issue with VMD itself, but rather the X server
and socket tunneling you're using. It seems that there's some sort
of problem with the SSH tunnel you're using to forward your
X server connection, which is why Tk is complaining about being unable
to connect to the display "localhost:10.0".

Your VMD seems to have successfully connected to a GLX X11 server
back-end that identifies itself as "Software Rasterizer", but things
appear to fail after that when Tk begins trying to initialize.

Are you wable to run the "wishx" Tk shell on this arrangement without
encountering that error?

What do you have your DISPLAY environment variable set to prior to
launching VMD?

Best regards,
  John Stone

On Wed, Feb 05, 2020 at 10:44:13AM +0900, George Mogami wrote:
> Dear all,
> I have used VMD installed in centos 6.8 from SSH connected PC.
> Some time ago, VMD became not available using X forwarding.
> Following is the log of VMD start:
> $ vmd
> Info) VMD for LINUXAMD64, version 1.9.2 (December 29, 2014)
> Info)
> Info) Email questions and bug reports to
> Info) Please include this reference in published work using VMD:
> Info) Humphrey, W., Dalke, A. and Schulten, K., `VMD - Visual
> Info) Molecular Dynamics', J. Molec. Graphics 1996, 14.1, 33-38.
> Info) -------------------------------------------------------------
> Info) Multithreading available, 28 CPUs detected.
> Info) Free system memory: 127916MB (99%)
> Info) Creating CUDA device pool and initializing hardware...
> Info) Detected 1 available CUDA accelerator:
> Info) [0] GeForce GT 710 1 SM_3.5 @ 0.95 GHz, 980MB RAM, AE1, ZCP
> Warning) Detected X11 'Composite' extension: if incorrect display occurs
> Warning) try disabling this X server option. Most OpenGL drivers
> Warning) disable stereoscopic display when 'Composite' is enabled.
> Info) OpenGL renderer: Software Rasterizer
> Info) GLSL rendering mode is NOT available.
> Info) Textures: 2-D (16384x16384), 3-D (512x512x512), Multitexture (8)
> MobaXterm X11 proxy: unable to connect to forwarded X server: Network error: Software caused connection abort
> ERROR) Tk startup error: couldn't connect to display "localhost:10.0"
> X I/O error
> If other process such as "xeyes" and "glxgears", I can display them normally.
> In text mode, "$ vmd -dispdev text", that works well.
> When I login centos workstation directly and startx, I can use VMD normally.
> Then, a problem seems to be around X forwarding setting.
> I tried uninstall and reinstall VMD or install of another version of VMD(1.9.3) in another directory.
> However, the same error occurred as above.
> How can I fix the issue?
> Thanks in advance.
> Best regards,
> George
> --
> *============================*
> George Mogami
> Assistant Professor
> Yamamoto Lab., Dept. Materials Processing,
> Graduate School of Engineering, Tohoku Univ.
> 6-6-02, Aramaki Aza Aoba, Aoba-ku,
> Sendai city, Miyagi, 980-8579, Japan
> *============================*

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