Animations won’t play

Step-through players run in your browser, so most fixes are quick.

1. Reload the page. If the lesson is open in a long-lived tab, close it and open it again.
2. Update your browser. Current versions of Chrome, Safari, Firefox and Edge are supported.
3. Turn off any extension that blocks scripts, such as an ad or script blocker, for this site.
4. Check that your device isn’t set to reduce motion. Some players pause when it is.

If it still fails, tell us the lesson link, your browser and your device so we can reproduce it.