# Cell with non-manifold triangulation
**URL:** https://discourse.paraview.org/t/cell-with-non-manifold-triangulation/15473
**Category:** ParaView Support
**Tags:** vtk
**Created:** [September 30, 2024, 9:39am UTC](https://discourse.paraview.org/t/cell-with-non-manifold-triangulation/15473 "2024-09-30T09:39:02Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Il\_Briga](https://discourse.paraview.org/u/Il_Briga)
#### Post date: [September 30, 2024, 9:39am UTC](https://discourse.paraview.org/t/cell-with-non-manifold-triangulation/15473/1 "2024-09-30T09:39:02Z")
Hello everyone,
My simulation runs perfectly and it converges both in PISO and SIMPLE mode (i.e unsteady and steady case). However viewing the result, when i apply a slice, the following warning is provided by Paraview:
```auto
Generic Warning: In vtkPolyhedron.cxx, line 1836
A cell with a non-manifold triangulation has been encountered. This cell cannot be contoured.
```
Have i to worry about this? How could this fact impact on my simulation? The comparison between numerical and experimental data is however quite good (at least i would not blame the numerical mesh about discrepancies, considering the turbulence model and the discretizion order i used).
Can you provide some impression about this? Thanks a lot!
---
### Author:  [@jerolsoibam21](https://discourse.paraview.org/u/jerolsoibam21)
#### Post date: [October 15, 2024, 7:25am UTC](https://discourse.paraview.org/t/cell-with-non-manifold-triangulation/15473/2 "2024-10-15T07:25:53Z")
Hi,
If you apply **Tetrahedralize** to you case file then this warning should go away. And you should be able to take the slice without any problem. However, what i have notice is that it requires additional computation to this and if you are exporting an animation or any form of files then it becomes super slow due the filter “Tetrahedralize”. The version of Paraview i am using is 5.12.0.
Here i put an example before applying Tetrahedralize filter.
In my case i am exporting the data from Fluent in Ensight Gold Format.
I tried with older version of Paraview 5.4.1 and this problem normally dont occur. This is something to do with the VTK i think.
Perhaps @mwestphal can highlight a bit more on this and how to fix with the newer versions of Paraview.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 21, 2024, 7:34am UTC](https://discourse.paraview.org/t/cell-with-non-manifold-triangulation/15473/3 "2024-10-21T07:34:30Z")
> [@jerolsoibam21](#):
>
> I tried with older version of Paraview 5.4.1 and this problem normally dont occur. This is something to do with the VTK i think.
The newer version of ParaView are warning where previous version were just incorrect without warning.
There is an issue in your polyhedron cells and ParaView tells you about it. You can ignore this warning if you want.