DLL load failure when importing vtkFiltersExtraction

Setup: Windows 10, Anaconda, Python v3.9

When I try to import vtkFiltersExtraction:

import vtkmodules.vtkFiltersExtraction

I get this error:

ImportError: DLL load failed while importing vtkFiltersExtraction: The specified module could not be found.

I can import other modules such as vtkCommonCore, vtkCommonMath, vtkCommonTransforms, etc.

When I look at the file “vtkFiltersExtraction-9.1.dll” stored in “C:/an39/Library/bin” with the Dependencies v1.10.0.0 app I don’t see anything unusual.


Alas, it is probably loading something else that can’t find its dependencies. It took until Python 3.10 for that error message to say what DLL wasn’t found or failed to load (the module name is just the trigger). ProcMon can be used to trace what DLL is actually failing (though it isn’t the easiest thing to use).