# AUR0105

## Error Message

`AUR0105: Ast eval error: unable to find $host context. Did you forget [au-slot] attribute?`

## Description

This error occurs when an expression uses `$host` but Aurelia cannot resolve the host context (commonly when using slotted content without the proper `[au-slot]` marker).

## Solution

* Ensure projected/slotted content is annotated as required (for example with `[au-slot]` where applicable).

## More Information

This code is also documented under the runtime-html section: [AUR0105](https://docs.aurelia.io/developer-guides/error-messages/runtime-html/aur0105).