# Error with vtkXMLReader.cxx file

**URL:** https://discourse.paraview.org/t/error-with-vtkxmlreader-cxx-file/8985
**Category:** ParaView Support
**Tags:** vtkm, vtk, python
**Created:** [February 16, 2022, 2:44pm UTC](https://discourse.paraview.org/t/error-with-vtkxmlreader-cxx-file/8985 "2022-02-16T14:44:34Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Lorenzo\_Marta](https://discourse.paraview.org/user_avatar/discourse.paraview.org/lorenzo_marta/32/8596_2.png) [@Lorenzo\_Marta](https://discourse.paraview.org/u/Lorenzo_Marta)
#### Post date: [February 16, 2022, 2:44pm UTC](https://discourse.paraview.org/t/error-with-vtkxmlreader-cxx-file/8985/1 "2022-02-16T14:44:34Z")

</div>

Hi everyone, I’m having problems with the interface between ParaView and vtk.  
(I’m working with macOS operating system on mac with M1 processor)  
In particular, starting from 2 files, meshR.vtu and Dxx.mhd, I have to build a third meshDxx.vtu which associates the values of the tensor built in Dxx.mhd to the meshR.  
Following a guide given to me, I ran the following command:  
`(base) Mac:Anima_data lorenzomarta$ vmtk myvmtkmeshDlabeling.py -ifile meshR.vtu -diffusionmapfile Dxx.mhd -diffusionarray "Dxx_labels" -ofile meshDxx.vtu`

and I get the following output:

```auto
Automatic piping myvmtkmeshDlabeling
Parsing options myvmtkmeshDlabeling
    MeshInInputFileName = meshR.vtu
    DiffusionMapInputFileName = Dxx.mhd
    DiffusionArrayName = Dxx_labels
    MeshOutOutputFileName = meshDxx.vtu
Explicit piping myvmtkmeshDlabeling
Input myvmtkmeshDlabeling members:
    Id = 0
    Disabled = 0
    MeshIn = None
    MeshInInputFileName = meshR.vtu
    DiffusionMap = None
    DiffusionMapInputFileName = Dxx.mhd
    DiffusionArrayName = Dxx_labels
    Correction = 0
    Radius = 9
    OnlyNegatives = 0
    MeshOutOutputFileName = meshDxx.vtu
Reading VTK XML mesh file.
ERROR: In ../IO/XML/vtkXMLReader.cxx, line 271
vtkXMLUnstructuredGridReader (0x7f860bf29ac0): Error opening file meshR.vtu

ERROR: In ../Common/ExecutionModel/vtkExecutive.cxx, line 784
vtkCompositeDataPipeline (0x600003f88000): Algorithm vtkXMLUnstructuredGridReader(0x7f860bf29ac0) returned failure for request: vtkInformation (0x600001192280)
  Debug: Off
  Modified Time: 136
  Reference Count: 1
  Registered Events: (none)
  Request: REQUEST_INFORMATION
  ALGORITHM_AFTER_FORWARD: 1
  FORWARD_DIRECTION: 0

Spacing 0.449219 0.449219 0.900000
Origin -105.647736 -123.984390 -68.281136
Dimensions 448 512 176
Executing myvmtkmeshDlabeling ...
Creating points location array
Assigning diffusion values to tethraedrical mesh
---Negative diffusion values found when mapping to 3D mesh: 0
---Null diffusion values found when mapping to 3D mesh: 0
Done executing myvmtkmeshDlabeling.
Writing VTK XML mesh file.
Output myvmtkmeshDlabeling members:
    Id = 0
    MeshOut = vtkUnstructuredGrid

```

I don’t understand what the 2 errors that pop up depend on.  
The meshDxx.vtu file in paraview does not allow me to view anything and gives me an error signal.