Sorry about the issue.
If you hard reload the page in your browser, which clears the cache, it should work again.
You can do that by using:
Windows: Control F5
Mac: CMD R
There are instructions here:
If that doesn't work, please let me know and we can try to figure out what else might be happening.
There is a thread here in the Author Hangout as well:
Thank you for any more info you can share.