This listener is invoked when the upload or download fails for any of the following reasons:
An input/output error occurs while the player is reading, writing, or transmitting the file.
The SWF file tries to upload a file to a server that requires authentication, such as a user name and password. During upload, Flash Player does not provide a means for users to enter passwords. If a SWF file tries to upload a file to a server that requires authentication, the upload fails.
The SWF file tries to download a file from a server that requires authentication, in the stand-alone or external player. During download, the stand-alone and external players do not provide a means for users to enter passwords. If a SWF file in these players tries to download a file from a server that requires authentication, the download fails. File download can succeed only in the ActiveX control and browser plug-in players.
The value passed to the url parameter in upload() contains an invalid protocol. Valid protocols are HTTP and HTTPS.
Important: Only Flash applications that are running in a browser -- that is, using the browser plug-in or ActiveX control -- can provide a dialog to prompt the user to enter a user name and password for authentication, and then only for downloads. For uploads that use the plug-in or ActiveX control, or that upload and download using either the standalone or external players, the file transfer fails.
Availability: ActionScript 1.0; Flash Player 8
Parameters
fileRef:flash.net.FileReference - The FileReference object that initiated the operation.
Example
The following example traces a message when the onIOError event is triggered. For simplicity, none of the other event listeners are included in this example.