Adobe will Actively Block Flash Content from Running Beginning January 12th of 2021

It has been widely publicized that the death of Flash was coming in December of 2020, the major browsers are removing support for it. While working on a Flash related issue I ran across Adobe’s EOL page that suggests a more extreme measure than I had assumed. The Flash Player itself has a timebomb in it that will prevent it from working after 1/12/2020. The news caught me and several of my fellow engineers off guard.

The official Adobe EOL page is at Adobe Flash Player End of Life and clearly says; “To help secure users’ systems, Adobe will block Flash content from running in Flash Player beginning January 12, 2021.” My first instinct was to turn off Flash updates, but according to an article published by ZDNET Adobe anticipated attempts to avoid the software’s demise. The kill switch was written into the Flash player code base long ago, updates are only modifying the warning message.

Microsoft will also be releasing an update to remove all traces of Flash from Windows systems. The update will be optional at first, then upgraded to recommended at some unknown date. The update will be permanent and can not be undone. For more details see their post on the subject at Update on Adobe Flash Player End of Support – Microsoft Edge Blog (

Both Adobe and Microsoft will be removing download links (many are already gone) for the older versions of Flash player software from their sites. All of the major browsers and even many of the secondary options have removed, or are removing support for Flash. This effort to end a piece of software’s use is the most aggressive that I can personally recall.

What can do if your organization still uses an app that requires Flash? Adobe has left one option available, Enterprise Enablement as outlined on page 28 (PDF page 33) of the Adobe Flash Player Administration Guide allows for the use of custom mms.cfg files to allow certain sites to still run Flash content. VMware’s document on the subject outlines how to use the files to allow its Flash based management console to continue working. Given that browsers and operating systems are also removing support, it is unclear how long a workaround of this nature will continue to function.

The bottom line is that Flash is being killed off completely. Much in the same manner as SHA1 certificates, it isn’t being left up to individual choice. The tech companies Adobe, Apple, Microsoft, Google, and others have banded together on this and we need to plan for the full demise of Flash Player.

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