This indicates that a JavaScript function couldn't be found. Most likely, a custom checkout is being used and not all JavaScript files from a module or from Magento itself are loaded properly.

To resolve this, make sure that the following files are loaded correctly:

  • all JavaScript files from the respective module, and
  • the default JavaScripts for the Magento checkout.

Technical background

The JavaScript functions are usually called like this:


If a function is not found in the given object, it results in the above TypeError. For more detailled information, see