# Connection / Inference Error: HTTPCallErrorError(description='500 Server Error

**URL:** <https://discuss.roboflow.com/t/connection-inference-error-httpcallerrorerror-description-500-server-error/11580>\
**Category:** 🤝  Community Help\
**Tags:** workflows\
**Created:** [December 10, 2025, 5:03pm UTC](https://discuss.roboflow.com/t/connection-inference-error-httpcallerrorerror-description-500-server-error/11580 "2025-12-10T17:03:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Iyouk](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/iyouk/32/8786_2.png) [@Iyouk](https://discuss.roboflow.com/u/Iyouk)\
**Post date:** [December 10, 2025, 5:03pm UTC](https://discuss.roboflow.com/t/connection-inference-error-httpcallerrorerror-description-500-server-error/11580/1 "2025-12-10T17:03:07Z")

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_Connection / Inference Error: HTTPCallErrorError(description=‘500 Server Error: Internal Server Error for url: [http://localhost:9001/okra-conveyorv2/workflows/custom-workflow-2](http://localhost:9001/okra-conveyorv2/workflows/custom-workflow-2)’, api\_message=‘The file lock ‘/tmp/model-cache/\_file\_locks/1.lock’ could not be acquired.. More details: The file lock ‘/tmp/model-cache/\_file\_locks/1.lock’ could not be acquired.’,status\_code=500)_

- **Project Type: roboflow workflow**
- **Operating System & Browser: RPI5 debian bookworm 64**
- **Project Universe Link or Workspace/Project ID:** okra-conveyorv2

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**Author:** ![Grzegorz](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/grzegorz/32/2877_2.png) [@Grzegorz](https://discuss.roboflow.com/u/Grzegorz)\
**Post date:** [December 10, 2025, 6:18pm UTC](https://discuss.roboflow.com/t/connection-inference-error-httpcallerrorerror-description-500-server-error/11580/2 "2025-12-10T18:18:41Z")

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Hi @Iyouk ,

Can you share how are you starting the container?

Thanks!

Grzegorz

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**Author:** ![system](https://canada1.discourse-cdn.com/flex029/uploads/roboflow1/original/1X/bb6edbfa56d0cf2ee603f061e9e09103502cc8cc.png) [@system](https://discuss.roboflow.com/u/system)\
**Post date:** [December 31, 2025, 6:19pm UTC](https://discuss.roboflow.com/t/connection-inference-error-httpcallerrorerror-description-500-server-error/11580/3 "2025-12-31T18:19:27Z")

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