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

# ExternalContainerDoesNotExist validation rule

> Validates that any container referenced by a view property, when the referenced container does not belong to the data model's space, exists in CDF.

This rule checks that, for each view property that maps to a container in a different space than the data model,
the referenced external container exists in CDF.

## Why it matters

If a view property references a container that does not exist in CDF,
the data model cannot be deployed. The affected view property will not function, and the
deployment of the entire data model will fail.

## Example

View `my_space:WindTurbine` has a property `location` that maps to container
`other_space:WindTurbineContainer`, where `other_space` differs from `my_space`. If that
container does not exist in CDF, the model cannot be deployed.

## Further reading

* [Validation rules](/cdf/deploy/neat/validation/index)