# Common Issues

#### `window.shoplift` is `undefined`

**Cause:** Your script is running before Shoplift's script has loaded.

**Fix:** Use a polling pattern to wait:

```javascript
function waitForShoplift(callback, maxAttempts = 50) {
  let attempts = 0;

  function check() {
    if (window.shoplift) {
      callback();
    } else if (attempts < maxAttempts) {
      attempts++;
      setTimeout(check, 100);
    } else {
      console.warn('Shoplift did not load within the expected time.');
    }
  }

  check();
}
```

#### `isHypothesisActive()` always returns `false`

**Possible causes:**

* The test is paused or inactive in the Shoplift dashboard
* The hypothesis ID is incorrect (check for typos, copy it fresh from the dashboard)
* The visitor doesn't meet the test's targeting criteria (e.g., wrong device type or country)
* Merchant preview mode is active (check for `?isShopliftMerchant=true` in the URL or sessionStorage key `Shoplift_Session`)

**Debug:**

```javascript
// Force the variant via URL to confirm the hypothesis ID is correct
// https://yourstore.com/?slVariant=your-hypothesis-id

// Then check in console
await window.shoplift.isHypothesisActive('your-hypothesis-id');
```

If the URL parameter override works but normal assignment doesn't, the test configuration in the dashboard needs attention.

#### Variant shows briefly then disappears (flicker)

**Cause:** Your code applies the variant, but another script or page re-render overwrites it.

**Fix:**

* Ensure your test code runs after the DOM element is stable
* Use CSS transitions instead of immediate DOM manipulation
* For elements loaded via AJAX, listen for the appropriate load/render event before applying the variant

#### Test data not appearing in analytics

**Possible causes:**

* `getVisitorData()` is called before the visitor has been assigned to any tests
* Your analytics platform's script hasn't loaded yet
* Consent hasn't been granted (if using `setAnalyticsConsent()`)

**Fix:** Ensure both Shoplift and your analytics platform are loaded before sending data:

```javascript
function init(maxAttempts = 50) {
  let attempts = 0;

  function check() {
    if (window.shoplift && window.yourAnalytics) {
      const data = window.shoplift.getVisitorData();
      if (data.visitorTests.length > 0) {
        // Send data
      }
    } else if (attempts < maxAttempts) {
      attempts++;
      setTimeout(check, 100);
    }
  }

  check();
}

init();
```

#### Consent integration not working

**Debug steps:**

1. Verify your CMP is loaded: `console.log(typeof OneTrust)` or `console.log(typeof Cookiebot)`
2. Check consent state: `console.log(window.OnetrustActiveGroups)` or `console.log(Cookiebot.consent)`
3. Manually test: `await window.shoplift.setAnalyticsConsent(true)`
4. Verify: `console.log(window.shoplift.getVisitorData())`