Note: Visit the Adobe Flash Player Help and Support page for help with top issues.
Note: This TechNote is intended for Adobe Flash and Adobe Flex developers who need to respond to changes in Adobe Flash Player 10's user interaction rules. End users with Flash Player install issues should begin troubleshooting at the Flash Player Support Center.
With Adobe Flash Player 10, the FileReference.browse and FileReference.download operations may be initiated only through ActionScript that originates from user interaction. This includes actions such as clicking the mouse or pressing the keyboard.
In Flash Player 9, ActionScript could perform uploads and downloads at any time. Flash Player 10 requires existing content to be updated to comply with stricter security rules.
This change can potentially affect any SWF file that makes use of Filereference.browse or FileReference.download. This change affects SWF files of all versions played in Flash Player 10 and later. This change affects all non-app content in Adobe AIR (however, AIR app content itself is unaffected).
Any existing content that invokes a browse dialog box using Filereference.browse, FileReference.download, or FileReference.save outside of an event triggered by user interaction will need to be updated. The dialog box will now have to be invoked through a button, keyboard shortcut, or some other event initiated by the user.
For further information see User-initiated action requirements in Flash Player 10.
One practical consideration that end users may have to make it the way they 'chain' events together.
For example, prior to Flash Player 10 you could use URLLoader to upload multiple files by having the onComplete() event of the first URLLoader create a new, 2nd URLLoader instance.
In Flash Player 10 this usage will violate the user interaction rules and throw a Security Sandbox Violation which will usually look like this:
*** Security Sandbox Violation *** Connection to http://www.adobe.com/test/upload.php halted - not permitted from http://www.adobe.com/test/uploadtest.swf SecurityError: Error #2176: Certain actions, such as those that display a pop-up window, may only be invoked upon user interaction, for example by a mouse click or button press.