Over the last few weeks I have been brushing up on my VDI skills. Specifically VMware View running non-persistent Windows 7 desktops with IE11 installed. To guarantee compatibility with legacy applications and sites we utilized IE11 Enterprise mode with a website list. The Enterprise Mode “SiteList” list is pushed by Group Policy to HKEY_LOCAL_Machine hosted on an internal website.
Using the Enterprise Mode website list xml tool to update the URL’s to run in Enterprise Mode was simple, and all the VDI clients received the location and correct version of the list. Unfortunately what we ran into was Enterprise Mode not initializing on websites that were marked to run in Enterprise Mode. This was random which made troubleshooting difficult since the VDI desktops are deleted when a user logs off. To make the problem even harder to diagnose, users would work fine all throughout the day, while other users would never initialize in Enterprise Mode to begin with. One would think when in a non-persistent desktop environment there shouldn’t be a variance of user experience.
After exhausting Google and no documentation describing this issue, I had to open a ticket with Microsoft. Tier 3 confirmed this was a known bug (Tier1/2 were clueless).
The issue is when a user logs off their desktop is deleted in a non-persistent environment. Any settings that are stored locally are gone. Specifically the “AppData” folder is deleted by default on logoff. If the user logs back on to a new desktop, IE will no longer use enterprise site list. This is because when a profile gets deleted, the cache container storing the Enterprise Mode Site List gets deleted, but the version key in the registry does not. Then when the user logs back on, IE makes the request for the Enterprise Site List after the usual 65 seconds, but does NOT update the cache container since the version from the server matches what’s in the registry. IE therefore runs with no enterprise site list.
The workaround / fix is to create a logoff/logon script that deletes the key-
Also verify if you have turned on the setting – Tools -> Internet options > Advanced > Empty Temporary Internet Filed Folder when browser is closed -> This could also impact the behavior of a site loading in Enterprise mode without log off. If this settings is turned on disable it.
Just another challenge in a non-persistent VDI desktop environment, which has presented no shortage of issues to overcome. Call me old school but persistent VDI Desktops utilizing the System Center stack with all the virtualization features enabled is the only way to go. Hell I would even take the MS RDS Pooled architecture and not deleting the template on logoff over pure non-persistent 🙂