On TumorSim 1.2, in both Windows and Linux I get the following error, when trying to run the program with the input files on the site

In Windows:

itk::ImageFileReaderException (0000000000AAB0C0)
Location: "unknown"
File: c:\work\itk-4.2.1\modules\io\imagebase\include\itkImageFileReader.hxx
Line: 143
Description:  Could not create IO object for file C:\Users\antonio\Documents\Tum
orSim\TumorSimInput1/labels.mha
The file doesn't exist.
Filename = C:\Users\antonio\Documents\TumorSim\TumorSimInput1/labels.mha

In Ubuntu (64 bit):
Reading VTK mesh...
ERROR: In /scratch/prastawa/VTK-5.10.0/IO/vtkDataReader.cxx, line 462
vtkUnstructuredGridReader (0x3300580): Unable to open file: /home/antonio/Documents/TumorSim/TumorSimInput2/mesh.vtk

Reading voxel labels...
itk::ImageFileReaderException (0x330fd80)
Location: "void itk::ImageFileReader::GenerateOutputInformation() [with TOutputImage = itk::Image, ConvertPixelTraits = itk::DefaultConvertPixelTraits]"
File: /scratch/prastawa/ITK-3.20.0/Code/IO/itkImageFileReader.txx
Line: 146
Description:  Could not create IO object for file /home/antonio/Documents/TumorSim/TumorSimInput2/labels.mha
The file doesn't exist.
Filename = /home/antonio/Documents/TumorSim/TumorSimInput2/labels.mha

In both cases the labels.mha file is treated as non-existing. Why?