---
page_type: error
code: 40000
message: "40000: Content-Type of 'application/json' not set"
level: ERROR
product: TaskRouter
---

### Content-Type of 'application/json' not set

#### Possible Causes

- You responded with a 200 HTTP response but did not provide a Content-Type header of 'application/json'

#### Possible Solutions

- Add Content-Type header of 'application/json'

#### Example

```.json
{
	"instruction": "accept"
}
```

with no Content-Type header provided.