# Slicer build errors on Window 7

**URL:** <https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642>\
**Category:** Support\
**Created:** [April 29, 2019, 3:52pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642 "2019-04-29T15:52:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![smrolfe](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/smrolfe/32/3659_2.png) [@smrolfe](https://discourse.slicer.org/u/smrolfe)\
**Post date:** [April 29, 2019, 3:52pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642/1 "2019-04-29T15:52:03Z")

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Hello,  
My Slicer build on a Windows 7 machine is failing due to errors building ITK and VTK. I’ve previously built Slicer on a Windows 10 machine and am using the same settings with the exception of unchecking the Slicer\_USE\_GIT\_PROTOCOL option since this machine is behind a firewall.

The build is failing to build both ITK and VTK. The VTK error message is:

> 56\>CMake Error at CMakeLists.txt:778 (find\_package):  
> 56\> Could not find a package configuration file provided by “VTK” (requested  
> 56\> version 8) with any of the following names:  
> 56\>  
> 56\> VTKConfig.cmake  
> 56\> vtk-config.cmake  
> 56\>  
> 56\> Add the installation prefix of “VTK” to CMAKE\_PREFIX\_PATH or set “VTK\_DIR”  
> 56\> to a directory containing one of the above files. If “VTK” provides a  
> 56\> separate development package or SDK, be sure it has been installed.

ITK is also failing to find the corresponding configuration files. I would appreciate advice on what could cause this kind of error.

Thanks,  
Sara

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [April 29, 2019, 3:55pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642/2 "2019-04-29T15:55:36Z")

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Has VTK and ITK build completed successfully? (do you see all the VTK dlls in c:\D\S4D\VTK-build\bin…?) If not, then there is an error before these errors are displayed that you need to address first.

Windows7 is not supported anymore by Microsoft, so I don’t think Slicer developers should still support it.

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**Author:** ![smrolfe](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/smrolfe/32/3659_2.png) [@smrolfe](https://discourse.slicer.org/u/smrolfe)\
**Post date:** [April 29, 2019, 4:15pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642/3 "2019-04-29T16:15:58Z")

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Thanks @lassoan. I checked and the VTK dlls are not being built. It looks like this error may be the root cause:

> 28\>Error downloading object: data/sample.cosmotools (9dc6346): Smudge error: Error downloading data/sample.cosmotools (9dc63465d864ec7a4546f1d006ca0153a5bb4c78fd4a42d16ad1177dabc70d75): batch response: Post [https://gitlab.kitware.com/vtk/vtk-m.git/info/lfs/objects/batch:](https://gitlab.kitware.com/vtk/vtk-m.git/info/lfs/objects/batch:) x509: certificate signed by unknown authority  
> 28\>  
> 28\>Errors logged to C:\S\_B\VTK.git\modules\VTK-m\lfs\logs\20190426T120855.9153945.log  
> 28\>Use `git lfs logs last` to view the log.  
> 28\>CUSTOMBUILD : error : external filter ‘git-lfs filter-process’ failed  
> 28\>fatal: data/sample.cosmotools: smudge filter lfs failed  
> 28\>Unable to checkout ‘8d0f441e1b391c6ec4c2662ee1454d8c901733fb’ in submodule path ‘ThirdParty/vtkm/vtk-m’

This looks like it’s still using the git protocol to get VTK, despite this option being disabled in the cmake file? Could this be an issue related to using Windows7?

Thanks,  
Sara

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**Author:** ![jamesobutler](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jamesobutler/32/7511_2.png) [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)\
**Post date:** [April 29, 2019, 4:18pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642/4 "2019-04-29T16:18:59Z")

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If you are reusing a build folder, when was the last time you built successfully? If you haven’t built since the transition from ITKv4 to ITKv5 (about a month ago), you’ll want to do a clean build. There have been some other major changes that have required a new clean build to get up-to-date with the current Slicer nightly.

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**Author:** ![smrolfe](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/smrolfe/32/3659_2.png) [@smrolfe](https://discourse.slicer.org/u/smrolfe)\
**Post date:** [April 29, 2019, 4:24pm UTC](https://discourse.slicer.org/t/slicer-build-errors-on-window-7/6642/5 "2019-04-29T16:24:35Z")

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Thanks @jamesobutler, I am starting from a fresh build folder.