# AUR3502

## Error Message

`AUR3502: Unexpected expression kind %s`

## Description

This error indicates the route expression parser encountered an expression kind it did not expect. In normal use, this should not happen and may indicate a router bug.

## Troubleshooting

* If you can reproduce, please report it with a minimal reproduction.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.aurelia.io/developer-guides/error-messages/router/aur3502.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.