Adobe® Flex 4.5.1 SDK Release Notes

Welcome to the Adobe Flex 4.5.1 SDK release.

About Flex

Flex SDK includes the Flex framework (also known as the Flex class library), Flex command-line compilers, the Flex debugger, the ASDoc utility, and the debugger version of Adobe® Flash® Player and Adobe® AIR® runtimes. Use the Flex SDK to develop, compile, and deploy Flex applications that connect to XML and SOAP web services or connect to various server technologies such as PHP, Adobe® ColdFusion®, Java, and .NET using a server technology such as BlazeDS. Flex applications can be built and configured to target browsers via the Flash Player runtime and desktops or mobile devices via the AIR runtime.

What's New

This Flex 4.5.1 SDK build is and contains:

  • Flash Player
  • TLF
  • OSMF

We strongly suggest you DO NOT overlay different AIR, AIR SDK or Flash Player versions into Flex 4.5.1 SDK build Development, debugging and deployment workflows are only certified with the AIR and Flash Player versions installed with the Flex SDK.

Install Your Software

Installation instructions

The Flex SDK installation is delivered as a ZIP file and contains the Flex framework, Adobe AIR framework, and command-line tools, such as the mxmlc command-line utility, Adobe AIR command-line utility, the ASDoc utility, the Flex command-line debugger, and the debugger version of Flash Player.

Uninstall current Flash Player

You should use Flex SDK with the latest version of the debug Flash Player 10. Prior to installing the Flex SDK, you should uninstall your current Flash Player.

Windows–Plugin-based browsers

Run the appropriate uninstaller available from this Tech Note.


Run the appropriate uninstaller available from this Tech Note.


Manual removal (for users who installed the plug-in via Install script):

  • Delete the binary and the flashplayer.xpt file in directory /home/<user>/.mozilla/plugins/

RPM removal:

  1. As root, enter the following command: 

    # rpm -e flash-plugin
  2. Click Enter and follow the prompts.

Install the Flex SDK

  1. Download Flex SDK ZIP file from the Adobe Website or the Adobe Open Source site.

  2. Create a directory to contain Flex SDK.

  3. Extract the Flex SDK ZIP file to this directory. The Flex SDK contains the following directories:

    • /ant — Contains Flex Ant Tasks.
    • /asdoc — Contains helper files for the ASDoc tool that creates HTML documentation from your MXML and ActionScript source code.
    • /bin — Contains the mxmlc, compc, asdoc, and fdb utilities. The bin directory also contains the jvm.config file, which specifies Java settings that you can modify, if necessary.
    • /frameworks — Contains compiled framework classes, configuration files, and framework source code.
    • /lib — Contains JAR files used by the utilities.
    • /runtimes — Contains installers for the Adobe AIR runtime inside the air directory and installers for debug versions of Flash Player 9 inside the player directory.
    • /samples — Contains sample applications.
    • /templates — Contains HTML templates for Flash Player detection and browser integration and inside the air folder, a sample Adobe AIR application.xml file.
  4. Ensure that the Java Runtime Environment (JRE) is installed on the computer and that the java_home/bin directory is defined in the system path. JRE 1.5,or 1.6 is required.

  5. Install the appropriate debug Flash Player from the install_root/runtimes/player/platform directory.

  6. (Optional) When the Flash Player installation finishes, restart your computer to ensure that the updated Flash Player browser plug-in is enabled.

Compatibility Issues

There have been some changes made in Flex 4.5 SDK that alter certain behaviors compared to Flex 4. To get the full list of issues, please refer to the Flex Backwards Compatibility document. In most cases, you can maintain Flex 4 (or even Flex 3) behavior by using the compiler argument, -compatibility-version.

Using the Data Visualization Components with Flex SDK

As of Flex 4, the data visualization components are part of the full SDK distribution.

Using Automated Testing with Flex SDK

As of Flex 4, automated testing support is part of the full SDK distribution.

Known Issues and Notable Changes

This section contains selected known issues and notable changes since the previous release. For a complete list of Flex issues and their status, see the public bugbase. The public bugbase lets you search for known issues, comment on them and add new bugs.

Tip: Use Filters to customize your search.

Text with Flex Mobile projects targeting Apple iOS

Editable text components should not be placed inside a Scroller. Focused text controls will not be clipped, which can cause the text to be overlayed on top of the ActionBar or TabBar.  We recommend keeping editable text components on the top half of the screen or pushing a new screen for editing each individual item. Please see this tech note for more information.

Packaging applications for Apple iOS with Flex 4.5.1

Flex applications do not perform well on iOS when developed and packaged with Flex SDK 4.5.1 command-line tools.  We recommend packaging applications for iOS using the AIR 2.7 command line packager (adt) - please see this tech note for more information. 

SDK-30625 -  RTE when re-orienting while SplashScreen is up

For a Flex Mobile project running in debug mode, the Application may throw a benign null-pointer RTE during a portion of the start-up application sequence if device orientation changes at that time. The RTE will bring up the standard Flash "uncaught exception" dialog if the application is running in ADL. The RTE may be noticed if running a debug session of the application either in ADL or on device. If encountered while debugging, the work around is to continue with the debugging session/dismiss the RTE. The RTE doesn't have an effect on the application and no work around is needed for release builds. 

SDK-30277 - Xoom device briefly reorients itself to landscape during launch if an AIR application is launched in portrait orientation

Applications with autoOrients set to true that are launched on a Motorola XOOM, where the physical device orientation is portrait, may result in the application reorienting to landscape and back to portrait at launch. 

© 2011 Adobe Systems Incorporated. All rights reserved.

Adobe, AIR, Flash Builder, Flex and LiveCycle are either registered trademarks or trademarks of Adobe Systems Incorporated in the United States and/or other countries.

iPhone and iOS are trademarks of Apple Inc., registered in the U.S. and other countries. 




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