# Error while Running CMAKE configure on VTK9.0 in Ubuntu

**URL:** https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688
**Category:** Support
**Created:** [May 3, 2021, 12:45pm UTC](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688 "2021-05-03T12:45:59Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Homersbm](https://discourse.vtk.org/user_avatar/discourse.vtk.org/homersbm/32/3328_2.png) [@Homersbm](https://discourse.vtk.org/u/Homersbm)
#### Post date: [May 3, 2021, 12:46pm UTC](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688/1 "2021-05-03T12:46:00Z")

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- Environment: Ubuntu:20.04.2 LST
- Compiler: G++ 9.3.0
- CMAKE Version: 3.20.2 -
- Generator - Unix MakeFIles
- vtk version: 9

I get the following error:  
Could NOT find X11 (missing: Xt)  
CMake Error at CMake/vtkModule.cmake:4140 (message):  
Could not find the X11 external dependency.  
Call Stack (most recent call first):  
Rendering/OpenGL2/CMakeLists.txt:334 (vtk\_module\_find\_package)

Configuring incomplete, errors occurred!

I have tried running “sudo apt-get install libx11-dev” but it didnt help

I have cmakeError.log but am not allowed to attaché the file

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### Author: ![DavidMiraut](https://discourse.vtk.org/user_avatar/discourse.vtk.org/davidmiraut/32/3329_2.png) [@DavidMiraut](https://discourse.vtk.org/u/DavidMiraut)
#### Post date: [May 3, 2021, 3:17pm UTC](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688/2 "2021-05-03T15:17:50Z")

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> [@Homersbm](#):
>
> Could NOT find X11 (missing: Xt)

I’m working on Windows, but I guess you could miss some headers in order to compile on Ubuntu.  
May be, you need libxt-dev because of the error message.  
Have you tried `sudo apt-get install libxt-dev` then rerun CMake?  
I’m not sure, I hope it could help.

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<div class="post-metadata">

### Author: ![Homersbm](https://discourse.vtk.org/user_avatar/discourse.vtk.org/homersbm/32/3328_2.png) [@Homersbm](https://discourse.vtk.org/u/Homersbm)
#### Post date: [May 4, 2021, 5:32am UTC](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688/3 "2021-05-04T05:32:59Z")

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sudo apt-get install libxt-dev helped. Thanks 🙂