# Experiment "Failed to Run"

**URL:** <https://forum.langchain.com/t/experiment-failed-to-run/2131>\
**Category:** Observability & Evals\
**Created:** [November 8, 2025, 2:03am UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131 "2025-11-08T02:03:44Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![aerickson-clt](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/aerickson-clt/32/501_2.png) [@aerickson-clt](https://forum.langchain.com/u/aerickson-clt)\
**Post date:** [November 8, 2025, 2:03am UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/1 "2025-11-08T02:03:44Z")

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I have run this experiment succesfully before and now it fails with no stated reason. Where can I find the reason and how can I fix this?

 ![image](https://canada1.discourse-cdn.com/flex007/uploads/langchain/original/2X/c/c1f0e29d5d820b773beddca4677e4c21e3bea946.png)

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**Author:** ![dhanlon](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/dhanlon/32/2132_2.png) [@dhanlon](https://forum.langchain.com/u/dhanlon)\
**Post date:** [November 11, 2025, 12:59am UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/2 "2025-11-11T00:59:28Z")

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I have been running into this too. getting 500 errors recently from the langgraph api with no major changes to the graph

[https://api.smith.langchain.com/datasets/studio\_experiment](https://api.smith.langchain.com/datasets/studio_experiment)

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**Author:** ![aerickson-clt](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/aerickson-clt/32/501_2.png) [@aerickson-clt](https://forum.langchain.com/u/aerickson-clt)\
**Post date:** [November 11, 2025, 5:44am UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/3 "2025-11-11T05:44:36Z")

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Link doesn’t work, can you provide some screenshots?

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**Author:** ![dhanlon](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/dhanlon/32/2132_2.png) [@dhanlon](https://forum.langchain.com/u/dhanlon)\
**Post date:** [November 11, 2025, 4:37pm UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/4 "2025-11-11T16:37:07Z")

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it was just the api url langgraph studio makes when trying to run an experiment. Server just returned 500 with no useful information

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**Author:** ![arjun](https://avatars.discourse-cdn.com/v4/letter/a/8e7dd6/32.png) [@arjun](https://forum.langchain.com/u/arjun)\
**Post date:** [November 13, 2025, 3:48pm UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/5 "2025-11-13T15:48:39Z")

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Hi All, This issue is resolved now.

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**Author:** ![dhanlon](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/dhanlon/32/2132_2.png) [@dhanlon](https://forum.langchain.com/u/dhanlon)\
**Post date:** [November 13, 2025, 6:45pm UTC](https://forum.langchain.com/t/experiment-failed-to-run/2131/6 "2025-11-13T18:45:19Z")

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You are my hero ❤