# Error running finalizers

**URL:** <https://discourse.julialang.org/t/error-running-finalizers/39247>\
**Category:** General Usage\
**Created:** [May 10, 2020, 9:33pm UTC](https://discourse.julialang.org/t/error-running-finalizers/39247 "2020-05-10T21:33:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![samuel\_okon](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/samuel_okon/32/10285_2.png) [@samuel\_okon](https://discourse.julialang.org/u/samuel_okon)\
**Post date:** [May 10, 2020, 9:33pm UTC](https://discourse.julialang.org/t/error-running-finalizers/39247/1 "2020-05-10T21:33:06Z")

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I sometimes get this error when running multi-threaded code (Basically nested @spawn calls) `error in running finalizer: ErrorException("concurrency violation detected")` . Does anyone know what could cause this?. The funny thing is that the error doesn’t stop my program or affect my results. I haven’t been able to trace the cause so i can’t provide a MWE. why It only happens after loading the function for the first time. Am running Generic Linux binaries with julia v1.4.1  
Any help would be appreciated

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**Author:** ![mkarikom](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mkarikom/32/7096_2.png) [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Post date:** [March 28, 2021, 11:34pm UTC](https://discourse.julialang.org/t/error-running-finalizers/39247/2 "2021-03-28T23:34:53Z")

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I’m having this issue as well, did you ever find a resolution?

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**Author:** ![samuel\_okon](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/samuel_okon/32/10285_2.png) [@samuel\_okon](https://discourse.julialang.org/u/samuel_okon)\
**Post date:** [March 29, 2021, 7:14pm UTC](https://discourse.julialang.org/t/error-running-finalizers/39247/3 "2021-03-29T19:14:54Z")

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In my use case, reducing the number of tasks being created seems to have helped. The problem might be related to [run finalizers on their own thread · Issue #35689 · JuliaLang/julia (github.com)](https://github.com/JuliaLang/julia/issues/35689)