> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Events appear intermittently or only on certain pages

> Events missing on some pages? A Shopify theme conflict — custom JavaScript throwing errors can interrupt the Upstack pixel. Use DevTools to find the offending script and isolate the conflict.

**Likely cause:** A Shopify theme conflict — custom JavaScript on your theme is throwing an error that interrupts the Upstack pixel before it finishes loading.

**Fix:**

1. Open your store in Chrome and press `F12` to open DevTools → **Console** tab.
2. Navigate through your store and look for red JavaScript errors. Common culprits include `Uncaught TypeError` or `$ is not defined` errors from other apps or custom code.
3. If errors appear on the same pages where events are missing, the offending script is blocking Upstack's execution.
4. Try temporarily disabling other third-party Shopify apps one at a time (via **App embeds**) to isolate the conflict.
5. Once identified, contact that app's support or move the conflicting script to load asynchronously.

***

**Still stuck?** Contact [support@upstackdata.com](mailto:support@upstackdata.com) with your Pixel ID and a description of the issue. We typically respond within a few hours.