# Warning: Particle has underwent  maximum number of events

**URL:** <https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222>\
**Category:** User Support\
**Created:** [June 23, 2016, 4:01pm UTC](https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222 "2016-06-23T16:01:02Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ALI](https://avatars.discourse-cdn.com/v4/letter/a/8c91f0/32.png) [@ALI](https://openmc.discourse.group/u/ALI)\
**Post date:** [June 23, 2016, 4:01pm UTC](https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222/1 "2016-06-23T16:01:02Z")

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Hi,

I am receiving a warning “Particle has underwent maximum number of events”, on running the model of a fuel assembly in openMC whose image is attached with this post. Can anyone explain what this warning means and possible reason for this?

![CFE.png](https://global.discourse-cdn.com/free1/uploads/openmc/original/1X/d2fc59e3c62b89d617c89a549426d47e71790121.png)

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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:** [June 29, 2016, 6:16am UTC](https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222/2 "2016-06-29T06:16:02Z")

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Hi Ali- what version of OpenMC are you running? This error is related to physics but might be caused by a bug that was fixed. If I know what version you’re running that will help to narrow down the possible causes.

Thanks,  
Paul

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**Author:** ![ALI](https://avatars.discourse-cdn.com/v4/letter/a/8c91f0/32.png) [@ALI](https://openmc.discourse.group/u/ALI)\
**Post date:** [July 2, 2016, 4:41pm UTC](https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222/3 "2016-07-02T16:41:47Z")

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Paul, I am using version 0.7.1. I have found the problem in the materials file and corrected it.

Regards,  
Ali

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**Author:** ![Bin\_Deng](https://avatars.discourse-cdn.com/v4/letter/b/d26b3c/32.png) [@Bin\_Deng](https://openmc.discourse.group/u/Bin_Deng)\
**Post date:** [December 6, 2018, 12:26pm UTC](https://openmc.discourse.group/t/warning-particle-has-underwent-maximum-number-of-events/222/4 "2018-12-06T12:26:00Z")

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Hello, ALI,  
I also meet the same problem with you, [Particle underwent maximum number of events]  
What’s the problem with your materials file? Hope to get your help!

Best regards,  
Benjamin

在 2016年7月3日星期日 UTC+8上午12:41:47，ALI写道：