Example to reproduce:

• Call in the browser console _paq.push(['hello', '//demo3.piwik.org/piwik.php', 1]);
• Got: JavaScript error in the browser console: TypeError: z[Y][ab] is undefined https://demo.piwik.org/piwik.js Line 22
• Expected: a useful error message in browser console such as `The method 'hello' does not exist in Piwik Tracker. See the list of methods at: http://developer.piwik.org/api-reference/tracking-javascript