> For the complete documentation index, see [llms.txt](https://docs.aurelia.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aurelia.io/developer-guides/error-messages/0203-to-0227/aur0206.md).

# AUR0206

## Error Message

`AUR0206: Trying to switch to a null/undefined connectable`

## Description

This error occurs when Aurelia’s internal connectable switcher is asked to switch to a connectable (an object participating in observation/connection) but the provided connectable is `null` or `undefined`.

## Example Trigger

This is usually caused by a bug in custom observer/connectable integrations or a lifecycle ordering issue where a connectable is disposed while still being used.

## Troubleshooting

* Ensure custom connectable implementations are created before use and not cleared too early.
* If you can reproduce this in a minimal example, please report it as it may indicate an Aurelia bug.


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