import _vtkmodules_static
ModuleNotFoundError: No module named '_vtkmodules_static'
>>>
```
How can I fix this problem?
CC @ben.boeckel @mwestphal @dgobbi
---
### Author:  [@adamgranthendry](https://discourse.vtk.org/u/adamgranthendry)
#### Post date: [September 5, 2021, 7:53pm UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/2 "2021-09-05T19:53:12Z")
Observing `C:\VTK\src\Wrapping\Python\CMakeLists.txt`, lines 169-182
```auto
set(vtk_build_paths_module
"${CMAKE_BINARY_DIR}/${VTK_PYTHON_SITE_PACKAGES_SUFFIX}/vtkmodules/_build_paths.py")
if (WIN32 AND VTK_DLL_PATHS)
string(REPLACE ";" "',\n '" vtk_dll_paths_python "${VTK_DLL_PATHS}")
file(WRITE "${vtk_build_paths_module}"
"paths = [\n '${vtk_dll_paths_python}',\n]\n")
# Add the file to the zip only if required in the install tree.
if (NOT VTK_RELOCATABLE_INSTALL AND NOT VTK_UNIFIED_INSTALL_TREE)
list(APPEND _vtk_python_files
"${vtk_build_paths_module}")
endif ()
elseif (EXISTS "${vtk_build_paths_module}")
file(REMOVE "${vtk_build_paths_module}")
endif ()
```
I notice `VTK_DLL_PATHS` is an empty string in CMake-GUI. Does this have to be set explicitly during configure/generate? Also, why isn’t this set by default if `VTK_RELOCATABLE_INSTALL` is set to OFF?
---
### Author:  [@adamgranthendry](https://discourse.vtk.org/u/adamgranthendry)
#### Post date: [September 5, 2021, 8:09pm UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/3 "2021-09-05T20:09:25Z")
Even setting
```bash
VTK_DLL_PATHS C:\VTK\bin
```
the Python module `_build_paths.py` is now created, which contains nothing more than
```python
paths = [
'C:/VTK/bin',
]
```
but the error still occurs.
@ben.boeckel @mwestphal @dgobbi I really need your help on this. Thank you in advance!
---
### Author:  [@dgobbi](https://discourse.vtk.org/u/dgobbi)
#### Post date: [September 5, 2021, 11:05pm UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/4 "2021-09-05T23:05:20Z")
The reason that `vtkCommonCore` doesn’t import is because it depends on DLLs that aren’t in Python’s DLL search path.
The first thing you need to do (and I think this has been suggested before), is to use a [good, modern dependency tracker](https://github.com/lucasg/Dependencies) to find all the DLLs that are needed. You can download the [DependenciesGUI](https://github.com/lucasg/Dependencies/releases/tag/v1.10) program, add it to your PATH, and then run it from within your bin directory:
```nohighlight
DependenciesGUI vtkCommonCore-9.0.dll
```
Or you can run it from within the vtkmodules directory:
```nohighlight
DependenciesGUI vtkCommonCore.cp38-win_amd64.pyd
```
Once you know what DLLs are needed, make sure they are all in the VTK\_DLL\_PATH. Just `C:\VTK\bin` by itself will be insufficient, it also needs the paths for the MPI DLLs, the TBB DLLs, and whatever other libraries you have linked to that aren’t in \Windows\System32.
---
### Author:  [@adamgranthendry](https://discourse.vtk.org/u/adamgranthendry)
#### Post date: [September 6, 2021, 5:12am UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/5 "2021-09-06T05:12:51Z")
@dgobbi You should notice that in the problem I report the issue is specifically with `vtkCommonCore`, which has solely to do with the core vtk dll, which does in fact exist in `C:\VTK\bin`. That being said, I also have the other pertinent dll’s in my PATH as well.
Why is it that `vtkCommonCore` would not load even though it is in my PATH?
---
### Author:  [@dgobbi](https://discourse.vtk.org/u/dgobbi)
#### Post date: [September 6, 2021, 5:27am UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/6 "2021-09-06T05:27:34Z")
The reason the `vtkCommonCore` DLL doesn’t load even though it is in the path, is that it needs other DLLs that are _not_ in the path.
In a bare-bones VTK build, `vtkCommonCore` will only depend on system libraries and VTK’s built-in utility libraries like KWSys. But you mentioned that you built with MPI (and perhaps other external third-party libraries?). The DLLs for all those additional libraries must be in the path.
---
### Author:  [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)
#### Post date: [September 6, 2021, 3:14pm UTC](https://discourse.vtk.org/t/cannot-import-build-paths/6555/7 "2021-09-06T15:14:20Z")
> [@adamgranthendry](#):
>
> You should notice that in the problem I report the issue is specifically with `vtkCommonCore`, which has solely to do with the core vtk dll
Yes, Python’s error message for this has always been terrible and there’s nothing we can do about that. However, 3.10 is said has useful information instead of misleading information in it.