# C1083: cannot open include file: 'vnl/vnl\_vector\_ref.h': No such file or directory

**URL:** <https://discourse.itk.org/t/c1083-cannot-open-include-file-vnl-vnl-vector-ref-h-no-such-file-or-directory/1115>\
**Category:** Beginner Questions\
**Created:** [July 12, 2018, 5:56pm UTC](https://discourse.itk.org/t/c1083-cannot-open-include-file-vnl-vnl-vector-ref-h-no-such-file-or-directory/1115 "2018-07-12T17:56:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![aharris](https://discourse.itk.org/letter_avatar_proxy/v4/letter/a/bcef8e/32.png) [@aharris](https://discourse.itk.org/u/aharris)\
**Post date:** [July 12, 2018, 5:56pm UTC](https://discourse.itk.org/t/c1083-cannot-open-include-file-vnl-vnl-vector-ref-h-no-such-file-or-directory/1115/1 "2018-07-12T17:56:57Z")

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Hi,  
I’m attempting to add a class that builds correctly on its own to a project that was originally built not using cmake. I should say it was working for quite a while, but at some point stopped working without a valid explanation, and I have attempted to restore the project to working condition thorough source control to no avail. I have added all the include directories to make the intellisense errors disapper in VS, but when I compile I get around a hundred identical errors on itkVector.h (which I assume is a dependent class because it’s not specifically included in my project anywhere). I have included the directory that contains vnl\_vector\_ref.h in the preferences for this project, however VS still cannot find it. In addition, I get an error that says is not supported when compiling with /clr or /clr:pure. Any suggested course of action would be helpful.

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**Author:** ![matt.mccormick](https://discourse.itk.org/user_avatar/discourse.itk.org/matt.mccormick/32/7_2.png) [@matt.mccormick](https://discourse.itk.org/u/matt.mccormick)\
**Post date:** [July 13, 2018, 3:07pm UTC](https://discourse.itk.org/t/c1083-cannot-open-include-file-vnl-vnl-vector-ref-h-no-such-file-or-directory/1115/2 "2018-07-13T15:07:45Z")

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Hi @aharris,

The best way to get to a working and maintainable solution is to convert the project to CMake.

I would recommend first reading through and executing the [Configuring and Building ITK](https://itk.org/ITKSoftwareGuide/html/Book1/ITKSoftwareGuide-Book1ch2.html#x22-130002) section of the ITK Software Guide, then checking the [CMake documentation](https://cmake.org/cmake/help/latest/) for more information.

Hope this helps,  
Matt

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**Author:** ![aharris](https://discourse.itk.org/letter_avatar_proxy/v4/letter/a/bcef8e/32.png) [@aharris](https://discourse.itk.org/u/aharris)\
**Post date:** [July 27, 2018, 9:51pm UTC](https://discourse.itk.org/t/c1083-cannot-open-include-file-vnl-vnl-vector-ref-h-no-such-file-or-directory/1115/3 "2018-07-27T21:51:46Z")

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I actually fixed this, so if anyone else is attempting to do something similar, it has to do with the path: I was including the directory vnl\_vector\_ref.h was contained in, but what I needed to do was include the directory that contained the directory path vnl/vnl\_vector\_ref.h

Hope that helps someone.