# Segmentation fault in Visualizer demo

**URL:** https://discourse.vtk.org/t/segmentation-fault-in-visualizer-demo/8112
**Category:** Support
**Created:** [March 22, 2022, 6:43pm UTC](https://discourse.vtk.org/t/segmentation-fault-in-visualizer-demo/8112 "2022-03-22T18:43:07Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![bala4krish](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@bala4krish](https://discourse.vtk.org/u/bala4krish)
#### Post date: [March 22, 2022, 6:43pm UTC](https://discourse.vtk.org/t/segmentation-fault-in-visualizer-demo/8112/1 "2022-03-22T18:43:08Z")

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Hello,

I am new to using VTK. Sorry if this very basic question. But I am unable to proceed with my own project. Can someone please help fix this?

I installed the `libvtk7-qt-dev` using the linux apt. My requirement is to use it with PCL. and so I started to off to follow a simple visualization tutorial ([here](https://pcl.readthedocs.io/projects/tutorials/en/latest/pcl_visualizer.html) ) from PCL (version 1.12) that uses VTK.

I got four cmake configure warnings (Import errors for “vtkParseOGLExt”, “vtkRenderingPythonTKWidgets”, “vtk”, “pvtk” ) as well that seems to be familiar in the community but there seems to be no solution to fix this (can someone help me to get rid of this as well, if you know a fix?). But I proceeded to build, and run the source file. The result is a seg fault as shown in in the attachment1.

 ![Screenshot from 2022-03-22 13-37-25](https://discourse.vtk.org/uploads/default/original/2X/a/af4d0f6ffb62065619a0e425caaa5f0f2d98de40.png)  
 ![Screenshot from 2022-03-22 13-38-52](https://discourse.vtk.org/uploads/default/original/2X/3/3b91a726a97e1bfc825d55fa52617326086943f0.png)

Asking help to proceed.

Thanks,  
Bala.