# Error while trying example of 'Modeling hexagonal lattices'

**URL:** <https://openmc.discourse.group/t/error-while-trying-example-of-modeling-hexagonal-lattices/649>\
**Category:** User Support\
**Created:** [July 20, 2020, 5:55am UTC](https://openmc.discourse.group/t/error-while-trying-example-of-modeling-hexagonal-lattices/649 "2020-07-20T05:55:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Karthik](https://avatars.discourse-cdn.com/v4/letter/k/9fc348/32.png) [@Karthik](https://openmc.discourse.group/u/Karthik)\
**Post date:** [July 20, 2020, 5:55am UTC](https://openmc.discourse.group/t/error-while-trying-example-of-modeling-hexagonal-lattices/649/1 "2020-07-20T05:55:28Z")

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Hi Paul Romano,  
I tried the example that is provided which is ‘Modeling of Hexagonal lattices’. But, I got error. The screenshots are attached. Would you be able to help me out. Thank You.

 ![Screenshot from 2020-07-20 10_45_43.png](https://global.discourse-cdn.com/free1/uploads/openmc/original/1X/47a688505a379b4354f184bcfcc5830cb297a689.png)

 ![Screenshot from 2020-07-20 10_42_43.png](https://global.discourse-cdn.com/free1/uploads/openmc/original/1X/093d14964d189291106a078426ac7b9cceaeaa68.png)

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**Author:** ![Pranto](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/pranto/32/489_2.png) [@Pranto](https://openmc.discourse.group/u/Pranto)\
**Post date:** [July 20, 2020, 7:04am UTC](https://openmc.discourse.group/t/error-while-trying-example-of-modeling-hexagonal-lattices/649/2 "2020-07-20T07:04:19Z")

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Can you restart your jupyter kernel by simply clicking **Kernel \> Restart and Run All** from the Jupyter menu?

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**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [July 21, 2020, 2:44pm UTC](https://openmc.discourse.group/t/error-while-trying-example-of-modeling-hexagonal-lattices/649/3 "2020-07-21T14:44:49Z")

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Hi Karthik,

The exception that is shown indicates that the OpenMC executable did not complete successfully. To get further information. I would advise going to a command line in the same directory where you have your Jupyter notebook and running ‘openmc -p’ directly, which will give you more information on the error when OpenMC was run in plotting mode.

Best,  
Paul