# Error in CGNSWriter

**URL:** https://discourse.paraview.org/t/error-in-cgnswriter/12544
**Category:** ParaView Support
**Tags:** mpi, vtk
**Created:** [July 19, 2023, 12:00pm UTC](https://discourse.paraview.org/t/error-in-cgnswriter/12544 "2023-07-19T12:00:09Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![fra](https://discourse.paraview.org/user_avatar/discourse.paraview.org/fra/32/6678_2.png) [@fra](https://discourse.paraview.org/u/fra)
#### Post date: [July 19, 2023, 12:00pm UTC](https://discourse.paraview.org/t/error-in-cgnswriter/12544/1 "2023-07-19T12:00:10Z")

</div>

Hi,  
I have a not so large EnSight Gold multiblock file (~9M cells). I have been trying to read it, perform some simple computations and then resave the data in CGNS. Whether I use (multiple instances of) a pvserver or a standalone Paraview client, upon saving I get the following errors:

```auto
 [paraview] vtkMPICommunicator.cxx:205 WARN| This operation not yet supported for more than 2147483647 objects
( 481.378s) [paraview] vtkExecutive.cxx:741 ERR| vtkPVCompositeDataPipeline (0x73e7b920): Algorithm vtkPCGNSWriter (0x3901b5e0) returned failure for request: vtkInformation (0x73e7bff0)
  Debug: Off
  Modified Time: 432928170
  Reference Count: 1
  Registered Events: (none)
  Request: REQUEST_DATA
  FROM_OUTPUT_PORT: -1
  ALGORITHM_AFTER_FORWARD: 1
  FORWARD_DIRECTION: 0

```

The error seems similar to this [MPI Integer Limit Error](https://discourse.paraview.org/t/mpi-integer-limit-error/7709), even though I don’t see why it should invoke a MPICommunicator in a standalone Paraview client (the writer seems also to be vtkPCGNSWriter, not sure why the parallel one is invoked). Any ideas?

---

<div class="post-metadata">

### Author: ![ben.boeckel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.paraview.org/u/ben.boeckel)
#### Post date: [July 20, 2023, 5:55pm UTC](https://discourse.paraview.org/t/error-in-cgnswriter/12544/2 "2023-07-20T17:55:51Z")

</div>

I believe that VTK was recently updated to support the larger ID space at least when the MPI implementation supports it (MPICH 4.1+).

Cc: @aron.helser @MicK7

---

<div class="post-metadata">

### Author: ![fra](https://discourse.paraview.org/user_avatar/discourse.paraview.org/fra/32/6678_2.png) [@fra](https://discourse.paraview.org/u/fra)
#### Post date: [July 23, 2023, 5:40pm UTC](https://discourse.paraview.org/t/error-in-cgnswriter/12544/3 "2023-07-23T17:40:00Z")

</div>

Why would a standalone Paraview client be bothered with MPI anyway?

---

<div class="post-metadata">

### Author: ![ben.boeckel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.paraview.org/u/ben.boeckel)
#### Post date: [July 23, 2023, 8:25pm UTC](https://discourse.paraview.org/t/error-in-cgnswriter/12544/4 "2023-07-23T20:25:19Z")

</div>

Local testing to see if the data is being split properly at least is at least one option. Some filters may also be parallelized over MPI but not threads.