Opening MMS via a URL in Windows Media Player on Citrix XenApp 6.5

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Kees Baggerman·Senior Technical Director at Nutanix – Former Citrix CTP – NVIDIA Enterprise Platform Advisor – 15+ years in EUC

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I was configuring a Citrix XenApp 6.5 farm and we created some instruction video’s for the users to get used to the new interface and structure, we offered those video’s (*.wmv) via a URL on a streaming server via MMS. So far so good but when clicking on the button linking to the wmv’s files the wmv’s wouldn’t start. Apparently this is a common problem because Citrix released a kb article on it: Citrix XenApp 6 is Unable to Open MMS Files

The title says Citrix XenApp 6 but when looking at the article it says:

This document applies to:

XenApp 6.0 for Windows Server 2008 R2

XenApp 6.5 for Windows Server 2008 R2

So I changed to following key:

"HKEY_CLASSES_ROOT\mms\shell\open\command_backup"

After a reboot of the server, when I tried to start the vmw’s I got the following error:

I figured it would be something to configure with Attachment Manager as explained here: Description of how the Attachment Manager works in Microsoft Windows

But after configuring the proper options I still would get this error. So I went searching on the internet and found a topic op the VMware forums saying you could disable the warning by creating a key:

Created registry key:  [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ProtocolExecute\horizon]

Created DWORD called “WarnOnOpen” and set value to “00000000”

Based on this key I tried to create the following key:

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ProtocolExecute\mms]

With a DWORD called WarnOnOpen with the value “00000000”

And after a reboot I was able to open the WMV without any warnings improving the user experience.

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Kees Baggerman

Kees Baggerman is Senior Technical Director — Performance & Solutions Engineering R&D at Nutanix, where he leads a global team responsible for defining how enterprise applications are delivered on the Nutanix platform. A former Citrix Technology Professional and NVIDIA Enterprise Platform Advisor, he has spent 15+ years driving EUC strategy and technical direction across architecture, product, and customer success. He has been writing here since 2011 — sharing what he learns at the intersection of platform engineering and enterprise IT.

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Kees Baggerman

Senior Technical Director at Nutanix - Former Citrix CTP - NVIDIA Enterprise Platform Advisor - 15+ years in EUC

Kees Baggerman is Senior Technical Director — Performance & Solutions Engineering R&D at Nutanix, where he leads a global team responsible for defining how enterprise applications are delivered on the Nutanix platform. A former Citrix Technology Professional and NVIDIA Enterprise Platform Advisor, he has spent 15+ years driving EUC strategy and technical direction across architecture, product, and customer success. He has been writing here since 2011 — sharing what he learns at the intersection of platform engineering and enterprise IT.

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