Google announced yesterday on Google+ that they are dropping all Flash based ads in their display ad network completely by January 2, 2017. All display ads will have to be HTML5, as opposed to Flash. In fact, by June 30, 2016, advertisers will no longer be able to upload display ads built in Flash to AdWords and DoubleClick Digital Marketing.
There is an exception, that "video ads built in Flash will not be impacted at this time."
Here is what Google wrote:
- Starting June 30th, 2016, display ads built in Flash can no longer be uploaded into AdWords and DoubleClick Digital Marketing.
- Starting January 2nd, 2017, display ads in the Flash format can no longer run on the Google Display Network or through DoubleClick.
It's important to update your display ads to HTML5 before these dates.
Google has a detailed help document on how you can manage moving from Flash to HTML5.