> For the complete documentation index, see [llms.txt](https://docs.uxwizz.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.uxwizz.com/guides/troubleshooting/tracking/the-a-b-test-js-file-is-missing.md).

# The A/B test JS file is missing

### Problem

The domain-specific file, such as `server/ab/example.com.ab.js`, returns **404 Not Found** after you include the A/B tracking snippet.

### Cause

A/B JavaScript is a generated file. It may not have been published for this domain, may have been removed, or may be blocked by the web server. A wrong domain or installation URL in the snippet can also cause a 404.

### Solution

#### A. If you are not using AB tests, include the tracking snippet without this feature

1. Open **Include the tracking pixel** for the affected domain.
2. Turn off **A/B tests**.
3. Copy the updated snippet and replace the old one on your website.
4. Clear the affected page or tag-manager cache, reload the site, and confirm it no longer requests the A/B file.

#### B. If you need A/B tests, publish the reviewed configuration

1. Open **A/B tests** for the correct domain.
2. Review the enabled tests and their variants, then select **Publish tests**. This writes the domain's A/B file and can change the live website's behavior.
3. If publishing fails, check the PHP error log and ownership of `server/ab/`. This needs server access; do not make the whole application world-writable.
4. Use the dashboard's generated tracking snippet and check that its exact A/B script URL returns successfully.

An empty test is not required merely to generate a file in current versions. Publishing is still an intentional action: it publishes the domain's enabled tests. Do not publish unreviewed drafts just to clear a console error.