Unable to publish to Flash format.
Since Adobe will no longer be supporting Flash Player after December 31, 2020 and Adobe will block Flash content from running in Flash Player beginning January 12, 2021, Adobe strongly recommends all users immediately uninstall Flash Player to help protect their systems.
For more information, see Flash Player End of Life announcement.
When you click Publish, you encounter the error rmessage,
Update Flash Player.
This error appears especially after you've updated your PowerPoint. PowerPoint is unable to create Flash objects after the new update.
Download and install the fix.
Download the zip file, unzip it, and double click the installer in the unzipped folder.
The fix allows you to publish projects to swf/html. The fix creates Flash objects only when it is required.
For the publish operation, the check for Flash output is only done when you click the option SWF.
Additionally, the fix checks the registry and allows the project to be published to SWF.
After applying this update, you cannot preview the project in Flash, although you can publish the project in Flash.
Previewing a project in HTML5 works as expected.