iron-icon.html causes unexpected Polymer.Base.create is not a function

[lruizr]

Description

The iron-icon element causes the own web-component does not load properly.

Expected outcome

The web component loads properly.
There are no errors in the console.

Actual outcome

The web-component does not load its content and the console shows the following error:
Uncaught TypeError: Polymer.Base.create is not a function
at iron-icon.html:142
Uncaught TypeError: Cannot read property 'tagName' of null

Live Demo

Steps to reproduce

We think there is no need to reproduce the steps. The main problem is to know where is the origin of the error message.

If it is needed, we can include a brief explanation.

Browsers Affected

• Chrome -> V