> ## Documentation Index
> Fetch the complete documentation index at: https://docs.maia.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Process nesting limit exceeded

> Resolve the error returned when a pipeline starts other pipelines more than 1,000 levels deep.

## Error message

```text wrap theme={null}
Unable to create child process - process nesting limit of 1000 has been exceeded
```

You might also see `failed to create child strand` in the error text.

This error can appear when using the following components: [Retry](https://docs.maia.ai/docs/components/retry.md), [Run Orchestration](https://docs.maia.ai/docs/components/run-orchestration.md), and [Run Shared Pipeline](https://docs.maia.ai/docs/components/run-shared-pipeline.md).

### Explanation

A pipeline started other pipelines so many levels deep that it hit the platform limit of 1,000 levels. This is almost always a pipeline that calls itself, directly or through a chain.

### Potential causes

* A pipeline loops by calling itself with a Run Orchestration component, so each pass nests one level deeper.
* A retry is built by calling the same pipeline again instead of using the component's own retry settings.
* A chain of pipelines calls back to an earlier pipeline in the chain.

***

## Resolve the error

1. Open the failed pipeline and follow the Run Orchestration and Run Shared Pipeline components to see whether any path leads back to a pipeline already in the chain.
2. Replace the recursive loop with a Loop component, such as a [Table Iterator](https://docs.maia.ai/docs/components/table-iterator.md) or [Grid Iterator](https://docs.maia.ai/docs/components/grid-iterator.md), which repeats work without adding nesting levels.
3. Replace self-calling retries with the retry settings on the component.
4. Make sure any loop has a condition that ends it.
5. [Validate the pipeline](https://docs.maia.ai/docs/guides/validating-pipelines.md) and run it again.
6. If you still need help, [contact Maia Support](https://support.matillion.com/s/) and include the items listed below.

   * The names of the pipelines in the call chain.
   * The root pipeline execution ID.

> [!NOTE]
>
> You can't raise the limit. Each level uses resources, so the fix is to change the pipeline design.

### Prevent future errors

To prevent this error occurring again, review any pipeline that calls itself before it goes to production.


## Related topics

- [Grid variable does not contain the expected column](https://docs.maia.ai/docs/errors/grid-variable-does-not-contain-the-expected-column.md)


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