# Error while importing the gmsh to PyFR

**URL:** <https://pyfr.discourse.group/t/error-while-importing-the-gmsh-to-pyfr/293>\
**Category:** Just Starting\
**Created:** [27 July 2020 14:37 UTC](https://pyfr.discourse.group/t/error-while-importing-the-gmsh-to-pyfr/293 "2020-07-27T14:37:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Chandra\_Shekhar\_Pant](https://avatars.discourse-cdn.com/v4/letter/c/439d5e/32.png) [@Chandra\_Shekhar\_Pant](https://pyfr.discourse.group/u/Chandra_Shekhar_Pant)\
**Post date:** [27 July 2020 14:37 UTC](https://pyfr.discourse.group/t/error-while-importing-the-gmsh-to-pyfr/293/1 "2020-07-27T14:37:41Z")

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Hello All,

I am very new to the group as well to the PyFR, so please excuse me for my naive query. I am trying to import a 3D cylinder mesh (from gmsh) to PyFR but getting the following errors:

Traceback (most recent call last):  
File “/home/csp/anaconda3/bin/pyfr”, line 10, in   
sys.exit(main())  
File “/home/csp/anaconda3/lib/python3.7/site-packages/pyfr/ **main**.py”, line 112, in main  
args.process(args)  
File “/home/csp/anaconda3/lib/python3.7/site-packages/pyfr/ **main**.py”, line 126, in process\_import  
mesh = reader.to\_pyfrm()  
File “/home/csp/anaconda3/lib/python3.7/site-packages/pyfr/readers/base.py”, line 20, in to\_pyfrm  
mesh = self.\_to\_raw\_pyfrm()  
File “/home/csp/anaconda3/lib/python3.7/site-packages/pyfr/readers/gmsh.py”, line 277, in \_to\_raw\_pyfrm  
rawm.update(mesh.get\_connectivity())  
File “/home/csp/anaconda3/lib/python3.7/site-packages/pyfr/readers/base.py”, line 196, in get\_connectivity  
raise ValueError(‘Unpaired faces in mesh’)  
ValueError: Unpaired faces in mesh

Even though I tried to get rid off the triangle cells, and now the gmsh report says that it has: 43510 Hexahedral and 15282 Quadrangles. I am facing this issue for couple of days, so any suggestion/comment will be a great help to me. Thanks in advance.

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**Author:** ![fdw](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@fdw](https://pyfr.discourse.group/u/fdw)\
**Post date:** [28 July 2020 00:47 UTC](https://pyfr.discourse.group/t/error-while-importing-the-gmsh-to-pyfr/293/2 "2020-07-28T00:47:21Z")

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Hi Chandra,

There is likely a problem with your .geo file which is causing Gmsh to  
generate a mesh with unpaired faces.

If you share your .geo file someone on the mailing list may be able to  
help you track down the specific issue.

Regards, Freddie.

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**Author:** ![Chandra\_Shekhar\_Pant](https://avatars.discourse-cdn.com/v4/letter/c/439d5e/32.png) [@Chandra\_Shekhar\_Pant](https://pyfr.discourse.group/u/Chandra_Shekhar_Pant)\
**Post date:** [28 July 2020 07:26 UTC](https://pyfr.discourse.group/t/error-while-importing-the-gmsh-to-pyfr/293/3 "2020-07-28T07:26:18Z")

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Hello Freddie,  
Many thanks for your prompt reply, as per your suggestion, I will take a closer look at the Gmsh file and will try to figure out the problem, if still the problem persist I will share the geo file in the group. Thanks again for your kind help and time.