---
page_type: error
code: 40100
message: "40100: TaskRouter->Reject"
level: ERROR
product: TaskRouter
---

## Description

Your Reject instruction does not include a valid `activity_sid` parameter.

### Possible Causes

- You did not include an `activity_sid` parameter in your `reject` instruction.
- You did include an `activity_sid` but it was invalid or no longer exists.

### Possible Solutions

- Confirm a valid `ActivitySid` value is is being passed by your code into the request payload JSON's `activity_sid` parameter: `{ "instruction": "reject", "activity_sid": "WA0123456789abcdef0123456789abcdef" }`