The Last Day of Flash
Google announced in June 2015 that its Chrome Browser would soon be able to pause content that was not "central" or essential to the Web page - and that day has come.
Starting tomorrow (September 1, 2015), a Chrome update will make Flash-blocking the default state for users, and will begin pausing many Flash ads by default to improve performance for users. If you're still running a Flash website or Flash ads, the experience provided to consumers/end-users will most definitely be affected.
For advertisers, Google recommends switching over to HTML5 ads to prevent blocking and has provided some support documentation to help manage the change. According to Google, most Flash ads that are uploaded to AdWords, however, are automatically converted.