HDX Flash Redirection is a technology that allows Flash-based videos to be rendered on the end user device (Windows or Linux) while appearing seamlessly integrated with the server-side web browser. HDX Flash provides a better user experience by offloading Adobe Flash rendering from the Citrix XenApp or XenDesktop server to the user device. The objective is to offload 80% or more of websites that leverage Flash. When Adobe Flash content cannot be redirected to the user device, the technology attempts to gracefully fall back to server-side rendering. Websites that cannot use Flash Redirection are blacklisted, either automatically by the software or manually by a system administrator.

If client-side Flash rendering is not desired, the HDX Flash Redirection technology can be disabled by using policies but the scalability benefits of HDX Flash Redirection are lost.

Compatibility Matrix

HDX Flash Redirection behavior might be affected by the Adobe Flash version, the XenApp or XenDesktop VDA version, as well as the Receiver version used to access applications and desktops. The browser version seems to have the largest impact on the specific Flash Redirection behavior that could be experienced in your environment.

Citrix has tested a variety of Adobe Flash and Internet Explorer versions against different XenApp and XenDesktop versions to determine the stability of Flash Redirection with these different combinations and to ensure that Flash Redirection works as expected.  The following matrix comprises the scope of our testing:

Note

• On July 25, 2017, Adobe announced End of Life (EOL) for Flash. Adobe plans to stop updating and distributing the Flash Player at the end of 2020. Microsoft announced that they are phasing out Flash support in Internet Explorer before the Adobe date. They are removing Flash from Windows by the end of 2020. When that happens, users can no longer enable or run Flash in Internet Explorer. Citrix aligns with Microsoft policy and continues to maintain and support HDX Flash Redirection until the end of 2020. More information available on https://docs.citrix.com/en-us/xenapp-and-xendesktop/7-15-ltsr/multimedia/flash-redirection.html 
• Adobe no longer has Extended Support Release (ESR) versions of Flash. Customers are recommended to use the supported versions of Flash as outlined in the matrix below.
• Some websites stream content using HTML5 by default, such as Youtube.com and may prompt to install Flash even after adding to Compatibility View. To use Flash Redirection on such websites, Emulation Mode should be used.(for example IE9 mode) The later section of the article outlines steps to enable Emulation Mode. 
• Beginning January 12, 2016, Microsoft supports only the most current version of Internet Explorer available for an operating system. Flash Redirection will be supported on the latest version of Internet Explorer supported on the operating system. For details, refer to Microsoft Lifecycle Support policy for Internet Explorer.

Citrix recommends the XenApp or XenDesktop component updates below used in our testing to achieve the best Flash Redirection experience.

These hotfixes contain several Flash Redirection related fixes that provide more stability to environments using Flash Redirection, particularly those which resulted in blacklisting websites and Flash videos not playing.

Website Content: Adobe Flash technology and content is frequently updated on many websites that might impact Flash Redirection particularly with Internet Explorer 11. Some of these website specific issues can be resolved by one of the following workarounds:

• Enable Internet Explorer Compatibility View and add the website(s) to the list.
• Enable Emulation Mode on the user device. In Internet Explorer, on the Tools menu, click F12 Developer Tools. In the far left of the DOM Explorer screen, scroll down the list and select the Emulation icon. In Document Mode, select 9 or 10. Microsoft Enterprise Mode Site List Manager can be utilized to automate the Document Mode.

List of Flash Related Articles

For more information, see the following articles: List of Flash Related Articles.

Installation and Configuration

CTX126529 - How to Enable Server-Side Content Fetching in HDX MediaStream for Flash

CTX124190 - How to Deploy and Configure HDX MediaStream for Flash

CTX125413 - How to Change the Background Color of Client-Rendered Flash Content for HDX MediaStream Flash Redirection

Known Issues and Limitations

CTX214127 - Citrix Known Issues With Adobe Flash Update 18.0.0.360

CTX214103 - Citrix Known Issues With Adobe Flash 22

CTX201150 - Adobe Flash 18 - Citrix Known Issues

CTX126702 - HDX MediaStream for Flash - Client-Side Content Fetching Limitations

CTX125324 - HDX MediaStream Flash Redirection - Network Latency Performance Issues

CTX124756 - HDX MediaStream for Flash Creates an Unknown Security Identifier in the ICA-tcp Port Permissions on Windows 2003 Feature Pack 2 Servers

CTX132751 - Windows Volume Control not working in VDA with HDX MediaStream for Flash v2

CTX128586 - HDX Monitor Tool Fails to Launch

CTX130847 - IMA Modules to Select when Recording a CDF Trace for a HDX MediaStream Flash Redirection Issues

CTX137799 - Internet Explorer 10 - Citrix Known Issues

CTX139939 - Microsoft Internet Explorer 11 - Citrix Known Issues

Troubleshooting

CTX134786 - Troubleshooting Flash V2 on Linux

CTX127188 - Troubleshooting Guide For Citrix HDX Components

CTX126491 - HDX Experience Monitor for XenApp

CTX135817 - HDX Monitor 3.x

CTX141595 - How to Enable HDX Flash Logging for Server-Side Rendering Failure

CTX126509 - Client Support for the XenApp HDX MediaStream for Flash Feature

CTX126817 - HDX MediaStream for Flash Feature Dynamic Blacklist Explained