This issue may occur due to a temporary error on your desktop. If the game keeps freezing, please follow the steps below to resolve the issue:
Update Your Browser, Flash and Java
Make sure that you use the latest version of your browser, Adobe Flash Player, and Java. Please refer to https://www.whatismybrowser.com for information about your browser settings.
Clear Out Cache and Cookies
Clearing the cache and cookies will allow the page to load faster and address certain crashing issues. Refer to the links below for instruction on clearing out your browsing history depending on your browser.
Instructions to Clear Cache/Cookies: