Modal Window Open Issue In Internet Explorer Only

I have a modal window (using bootstrap), with a close button. The modal window opens and closes fine in most browsers. However, in internet explorer, there is a problem. We can open the modal window fine, and close it fine ... but if we try to open it again, it wont.

When I click the open button a second time, there is an error in IE's console ... Object.keys: argument is not an Object. Note: this error doesn't occur the first time opening the modal window. Not sure how to fix it...

You can view the page here: https://www.amazingdg.com/_dev/temp/

Most of the javascript functionality is in bootstrap. Below is the html for the open button [I believe data-toggle="modal" and data-target="#exampleModal" are the key to opening the window]...
...and the html for the start of the modal window, with the close button [note the id="exampleModal" tells which window to open. And the data-dismiss tells to close "modal"...
Please help. Thanks.