Starting June 30, 2016, Google will no longer accept advertisements that
use Flash on the AdWords and DoubleClick networks. Instead, advertisers,
or those who create the online ads, are being urged use HTML5 instead.
And as of January 2, 2017, any ads with Flash still in the systems will
no longer play on DoubleClick or Google Display Network.http://www.v3.co.uk/v3-uk/news/2446512/google-to-ban-flash-ads-from-its-network