> For the complete documentation index, see [llms.txt](https://docs.dynamicmockups.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.dynamicmockups.com/getting-started/troubleshooting.md).

# Troubleshooting

Here you can find the most common issues you may encounter in our API integration.

## Missing "Accept: application/json" header

Our API returns a JSON-formatted response.

If your client does not accept application/json, you may encounter some weird responses such as HTML or not well-formatted response messages.

To avoid any confusion, always send the "**Accept: application/json**" header parameter in any API call.

## (401) Missing API Key

If you get 401 status code and the following response:

```json
{
    "message": "Unauthorized"
}
```

You are probably missing the **x-api-key** header in your API call or your API key is not valid.

To get your API Key you can create one visiting [API Dashboard](https://app.dynamicmockups.com/dashboard-api) page.

## (422) Invalid Mockup UUID

Our [Render API](/api-reference/render-api.md) requires **Mockup UUID** to know what mockup you want to render.

If you provided an invalid Mockup UUID or didn't provide it at all you may see this response:

```json
{
    "message": "The selected mockup uuid is invalid.",
    "errors": {
        "mockup_uuid": [
            "The selected mockup uuid is invalid."
        ]
    }
}
```

There are two ways to fix this issue.

One is to copy **Mockup UUID** from the web application URL. Example image below.

<figure><img src="/files/WPi0RBEejLbZc61X7iaF" alt=""><figcaption></figcaption></figure>

Another way is to call [Get Mockups API](/api-reference/get-mockups-api.md) to get all the available mockups from your account and their Mockup UUIDs.

## (422) invalid Smart Object UUID

Same as Mockup UUID, our [Render API ](/api-reference/render-api.md)requires **Smart Object UUID** to know what place inside a mockup you want to render and where you probably want to put your design asset.

If you provided an invalid Smart Object UUID you may see this response:

```json
{
    "message": "The selected smart_objects.0.uuid is invalid.",
    "errors": {
        "smart_objects.0.uuid": [
            "The selected smart_objects.0.uuid is invalid."
        ]
    }
}
```

There are two ways to fix this issue.

One is to copy **Smart Object UUID** from the web application URL. Example image below.

<figure><img src="/files/WPi0RBEejLbZc61X7iaF" alt=""><figcaption></figcaption></figure>

Another way is to call [Get Mockups API](/api-reference/get-mockups-api.md) to get all the available mockups from your account and their available smart objects with UUIDs.

## (400) Wrong file URL extension provided

When you provide the design asset you want to render on the mockup using [Render API](/api-reference/render-api.md), we accept the following file extensions: JPG, JPEG, PNG, WEBP, GIF

If you provide any other, such as SVG, you may see this response:

```json
{
    "success": false,
    "message": "Wrong file URL extension provided. svg is not supported. Supported values are: jpg, jpeg, png, webp, gif"
}
```

## Getting 500 server errors?

This is not an expected behavior from our API.

In this case, please [contact us](/getting-started/how-can-i-get-support.md) and we will resolve the issue as soon as possible.