> For the complete documentation index, see [llms.txt](https://en.help.firstline.cc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://en.help.firstline.cc/feature/channels/live-chat/troubleshooting.md).

# Troubleshooting

## Unable to display live chat

In some cases, you may not see the FIRST LINE live chat you expect on the website. Let's find out why. There are many reasons why live chat may not display. Learn about the most common reasons below:

### Check allowed domains

If you are experiencing display issues with live chat, such as not being able to read the screen, this may be because the domain of the embedded website is not included in your 'allowed domains' settings. To ensure smooth chat use, please check your settings and add the relevant domain.

<figure><img src="https://842546780-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MNRu7dk70ei7JV9HlW9%2Fuploads%2F0UqVT1mMlkKoXFZ7x1xz%2Fimage.png?alt=media&#x26;token=569d63cb-d9ef-4ecb-bc26-3d1f7040aa1e" alt=""><figcaption></figcaption></figure>

### **Check HTML**

First, make sure your website correctly includes the live chat HTML embed code. You can check it by following these steps:

* Visit your website in a browser.
* Right-click somewhere on the page, then select “View page source.”
* In the source code, search for the word “firstline”.

If you cannot find the corresponding code containing the “firstline” keyword in the page source:

* Please make sure you have embedded the chat box code on all pages of your website.
* Check whether any caching mechanism is running on the front end of the website. If so, try clearing all caches. For example, if you use Cloudflare, you may need to perform the corresponding purge action.

<figure><img src="https://842546780-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MNRu7dk70ei7JV9HlW9%2Fuploads%2FVd9S3rkcgGyNbTnwgFQa%2Fimage.png?alt=media&#x26;token=d801973e-b941-49e9-9e13-9848efc7a8fe" alt=""><figcaption></figcaption></figure>

### Check whether JavaScript is working

FIRST LINE live chat mostly uses JavaScript to handle data operations. In certain cases, such as browser security settings or a company's Content Security Policy (CSP), JavaScript may be affected. If you encounter an issue where the FIRST LINE chat box does not display correctly, here are some solutions:

#### **Disable content inspection mode**

Temporarily disable your browser's content inspection mode, then check whether live chat appears. This can ensure that no content inspection mode is interfering with the operation of FIRST LINE live chat.

#### CSPv3 **Settings**

FIRST LINE live chat now fully supports [Google strict CSPv3](https://csp.withgoogle.com/docs/strict-csp.html) security policy. This Google policy provides a higher security standard for most web services while ensuring smooth service operation:

```
Content-Security-Policy:
  object-src 'none';
  script-src 'nonce-{random}' 'unsafe-inline' 'unsafe-eval' 'strict-dynamic' https: http:;
  base-uri 'self';
```

To ensure FIRST LINE live chat works smoothly on your website, if you have set a Content Security Policy (CSP), please check whether it includes the necessary directives. You need to add 'self', 'unsafe-inline', and 'unsafe-eval' to the script-src directive.

* `'unsafe-inline'`: Allows inline JavaScript code or CSS styles to be used on the webpage.
* `'unsafe-eval'`: Allows text-to-JavaScript execution via eval.

These two settings will help the live chat tool work properly.

<figure><img src="https://842546780-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MNRu7dk70ei7JV9HlW9%2Fuploads%2FvtqA5hIxkYRFh7k1mLMG%2Fimage.png?alt=media&#x26;token=070fcd1a-0df2-4b82-a02d-7a5145470357" alt=""><figcaption><p>Related causes can be viewed through browser developer tools</p></figcaption></figure>

#### Browser extensions interference

Some browser extensions may prevent certain page elements from loading, which may include live chat. If you know you have such extensions enabled in your browser, try disabling them and then reload the page to see if the problem is resolved. Sometimes you can also add specific websites to the extension's exception list to ensure these extensions do not interfere with FIRST LINE's functionality.

### DOS protection

Our network automatically blocks potential DOS attacks. If too many users connect to FIRST LINE live chat under the same IP, a 420 error will be triggered. If you encounter a 420 error while using FIRST LINE live chat, please make sure your users are not intentionally or illegally triggering this error. At the same time, you may need to adjust your network security policy to ensure that other users can use the live chat service smoothly.