Enable Adobe Flash support for the VMware Horizon Administrator console

Adobe Flash is no longer supported after December 31, 2020, and currently disabled by default.

During my consulting work, I still see organizations that use Adobe Flash-based applications such as the VMware Horizon Administrator. VMware Horizon 7.10 has an HTML5 based Horizon Console that nearly feature-complete and replaces the Adobe Flash-based Horizon Console.

For organizations, it can difficult to manage there VMware Horizon environments below version 7.10 of VMware Horizon. This can be done by enabling Adobe Flash temporarily. Caution: Enabling Adobe Flash is a security breach for your environment. So use with caution!!!

With the following steps you can enable Adobe Flash support on a Windows:

  • Download Firefox 78.6.1 ESR, link
  • Create or edit the following file: ‘C:\Windows\SysWOW64\Macromed\Flash\mms.cfg’ with the following settings:
EOLUninstallDisable=1  
SilentAutoUpdateEnable=0  
EnableAllowList=1  
AutoUpdateDisable=1  
ErrorReportingEnable=1  
AllowListUrlPattern=https://fqdn-of-the-horizon-connection-server:443  
  • Replace the ‘AllowListURLPattern’ with the FQDN of the VMware Horizon Connection server or load balancer URL
  • Open Firefox and enter the VMware Horizon Connection server or load balancing URL

When you are still using the VMware Horizon Administrator make sure to upgrade your VMware Horizon environment. The end of general support for Horizon 7 is March 2021. Upgrade to minimal VMware 7.13 (has general support till October of 2022) or VMware Horizon 8.x.