There currently is an issue with the latest version if the Google Chrome web browser which is preventing the Play Button from preforming as intended.
Please follow these steps in order to launch your game via Google Chrome:
Step 1: Copy and paste the following URL into your Google Chrome Address Bar: chrome://flags/#enable-npapi
Step 2: Find Enable NPAPI and click the Enable link to Disable.
Step 3: Once the status appears as Disable, restart your browser.
Now you will be able to use the Play button with Google Chrome