An error occurred while saving the commentMartin M commented
It is possible to play video files in Acrobat in 2021, and the design workflow is very much unchanged from the days of Flash. As long as you are using native video formats (i.e. not SWF or FLV) you should be able to export Interactive PDFs from InDesign with video. The issue/warning message seems to stem from a a legacy Acrobat setting. Simply go to your Preference window in Adobe Acrobat and in the "3D and Multimedia" panel deselect "Use Flash Player for playing 3D and multimedia content". Why oh why this setting has not been removed by the Acrobat team or the Flash Uninstaller baffles me but, Adobe. Hopefully a software update will resolve this issue for the many millions of users that this impacts as it's not an obvious one. In the meantime we may need to advise our clients/end users to update their PDF preference in order for this to work smoothly. I hope this helps some of you out there who have been looking for a workable solution. Note: This comment is based on the latest release of InDesign 16.0.2 and Acrobat Pro DC (2020.013.20074) as of 28th January on Mac OS, with Flash Player uninstalled.