iron-form demo: Submit button doesn't work on IE 11

[st3wang]

Description

I'm trying to use the iron-form on one of our production page which has to support IE 11+. The submit button on page I created doesn't work on IE 11. I tried the submit button on the iron-form demo page and it doesn't work either.

The iron-form auto validation features is awesome! and we'd really like to use them in production if they are supported on IE 11, like they are on Chrome.

Expected outcome

Clicking submit should display json result.

Actual outcome

After filling in all fields on the first form and click submit, the json result doesn't display

Live Demo

iron-form demo

Steps to reproduce

1. Fill in required fields on the first form
2. Click on Submit
3. The form does not display json result

Browsers Affected

• Chrome
• Firefox
• Safari 9
• Safari 8
• Safari 7
• Edge
• IE 11
• IE 10

[st3wang]

Here is a simple demo to reproduce it: http://codepen.io/stewang/pen/ALNoGA
Open it on IE 11 and click on the submit button, you will get
Unable to get property 'parentElement' of undefined or null reference
from this line: Polymer.dom(event).localTarget.parentElement.submit();