# AttributeError: module 'jax.core' has no attribute 'ConcreteArray'

**URL:** <https://discuss.pennylane.ai/t/attributeerror-module-jax-core-has-no-attribute-concretearray/8236>\
**Category:** Demos\
**Created:** [March 17, 2025, 2:48pm UTC](https://discuss.pennylane.ai/t/attributeerror-module-jax-core-has-no-attribute-concretearray/8236 "2025-03-17T14:48:22Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![CatalinaAlbornoz](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/catalinaalbornoz/32/1196_2.png) [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\
**Post date:** [March 17, 2025, 9:44pm UTC](https://discuss.pennylane.ai/t/attributeerror-module-jax-core-has-no-attribute-concretearray/8236/2 "2025-03-17T21:44:06Z")

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Hi @MKK_QML , welcome to the Forum!

This is probably due to the version of JAX you’re using. If you use JAX version 0.4.33 you probably won’t see the issue. If you use JAX \>=0.5 then you probably will.

Check out [thread #8053](https://discuss.pennylane.ai/t/attributeerror-module-jax-core-has-no-attribute-concretearray-problems-using-jax-grad-circuit/8053/7) if you need some help on how to downgrade your JAX version.

Let us know if you’re having trouble downgrading or if you still face this issue after downgrading.

And please let us know if this worked to solve the issue!

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_[View the full topic](https://discuss.pennylane.ai/t/attributeerror-module-jax-core-has-no-attribute-concretearray/8236)._