# Paraview v6.0.1 in Linux shows: vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection after successful connection
**URL:** https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501
**Category:** ParaView Support
**Created:** [March 31, 2026, 7:08pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501 "2026-03-31T19:08:33Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Louis.DeLillo](https://discourse.paraview.org/u/Louis.DeLillo)
#### Post date: [March 31, 2026, 7:08pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501/1 "2026-03-31T19:08:33Z")
After installing Paraview v6.0.1 on our Linux HPC environment and running in client/server mode, we get the Warnings shown in the server-side logs shown below. The GUI running on the client shows the same Warning. Other than what those show, it appears that everything is running correctly. We are operating in a headless environment where X11 Forwarding is not configured. Also, no GPUs are on either the client, server, or HPC compute nodes. We did not see these warnings with v5.13.1.
From server-side output file:
```auto
Connecting to client (reverse connection requested)…
Connection URL: csrc://MYserver.ray.com:11111
Client connected.
( 11.226s) \[pvserver.67 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.73 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.87 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.46 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.50 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.53 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.55 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.56 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.57 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.227s) \[pvserver.59 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.60 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.62 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.226s) \[pvserver.64 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
( 11.227s) \[pvserver.65 \]vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection. DISPLAY=
```
We are running pvserver using a SLURM submit script with the following arguments:
srun --mpi=pmi2 --cpu-bind=cores --export=ALL -n 96 pvserver --force-offscreen-rendering --system-mpi --timeout=60 --sp=11111 --rc --client-host=[MYserver.ray.com](http://MYserver.ray.com)
---
### Author:  [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)
#### Post date: [March 31, 2026, 9:38pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501/2 "2026-03-31T21:38:25Z")
I’m curious: does forcing the offsreen mesa rendering mode by setting the environment variable `VTK_DEFAULT_OPENGL_WINDOW ` to `vtkOSOpenGLRenderWindow` then running `pvserver` prevent the warnings?
Background: on Linux, ParaView 6 and later attempts to load X11 if it is available, EGL if X11 is available, and then falls back to offscreen mesa if neither of those are available. If your system has X11 libraries installed, but your system is not configured to provide X, that may be causing these warnings.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [April 1, 2026, 2:09pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501/3 "2026-04-01T14:09:25Z")
This is indeed the expected behavior when running with the env var or without the `--opengl-window-backend` option.
I think this is an issue, the check should be silent.
@jaswantp
---
### Author:  [@Louis.DeLillo](https://discourse.paraview.org/u/Louis.DeLillo)
#### Post date: [April 1, 2026, 3:47pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501/4 "2026-04-01T15:47:05Z")
Thank you, guys. That worked. I just put the following entry in my SLURM submit script and the Warning no longer shows up:
export VTK\_DEFAULT\_OPENGL\_WINDOW=vtkOSOpenGLRenderWindow
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [April 17, 2026, 12:02pm UTC](https://discourse.paraview.org/t/paraview-v6-0-1-in-linux-shows-vtkxopenglrenderwindow-1458-warn-bad-x-server-connection-after-successful-connection/17501/5 "2026-04-17T12:02:17Z")
This warning can be ignored. Currently, only way to disable that warning from ever showing up is to set that env var (like you did) or the cli flag Mathieu shared.
Another user [requested](https://discourse.vtk.org/t/offscreen-rendering-with-vtk-9-4-vtkxopenglrenderwindow-warnings/14894) we log this message at higher verbosity like `TRACE`.