Roaming Edge Chromium - IE Mode

Background

In an earlier blog post, we explored how to roam the user preferences/settings for the new Microsoft Edge Chromium browser.  There was an outstanding question around how to handle IE Mode/EMIE which this post picks up on.

Since the GA release of Microsoft’s Edge Chromium Browser there have been three versions released on the stable channel at the time of writing:

• Stable 79.0.309.65
• Stable 79.0.309.68
• Stable 79.0.309.71

The following investigation has been completed using the 79.0.309.71 build.

Investigation

We won’t go into details around how to use the Enterprise Mode Site List Manager (schema v.2) or how to deploy an EMIE xml file here.  Suffice to say we used the site manager to create an XML file, configured the following policies to enable IE Mode and used the generated XML file for the configuration.

The policies were applied at the Computer level via standard AD Group Policy here but believe this can also be done at the User level.

Having enabled the above policies IE mode appears to be working.  Navigating to https://www.avanite.com (it was added to the site list) we can see that when IE Mode is configured we get an IE icon showing to the left of the URL bar:

Now a few observations on what is going on here.

EMIESiteList.xml and webcache

When Edge Chromium launches it checks the policies to see if the IE Integration has been enabled and where the EMIE Site List is stored.  If these are set, it downloads the EMIE Site List to the “%LocalAppData%\Microsoft\Edge\User Data” folder in the form of an EmieSiteList.xml file:

The Enterprise Mode Site List is also stored in the webcache database in a new container called “EmieSiteListDualEngine”.

This is indicated via the “%LocalAppData%\Microsoft\Internet Explorer\EmieSiteListDualEngine “ folder which contains a container.dat file only:

Diving into the webcache and its contents is one step too far for this blog so suffice to say this has been looked into by us here at Avanite.

Using IE Mode also generates a new folder in the “%LocalAppData%\Microsoft\Edge\User Data\Default” location called DualEngine:

Looking at this folder and its contents, it keeps a small file for every page viewed in IE Mode.

DualEngineAdapter

When IE Mode is used, looking in task manager or Sysinternals procmon we see that msedge.exe has launched iexplore.exe with a special command line:

The “Use Microsoft Edge with IE mode” article (https://docs.microsoft.com/en-gb/deployedge/edge-ie-mode#prerequisites) discusses the pre-requisites for Edge Chromium IE mode and our best guess would be that minimum operating system versions are required as there have been some updates to Internet Explorer pushed out to support launching via the “-dualengineadaptor” parameter.  Edge Chromium is reliant on Internet Explorer to provide the IE Mode functionality, hence when Internet Explorer is uninstalled it no longer works.

Roaming IE Mode Settings

Using the setup from the previous blog there was no consideration for roaming the IE mode settings.  When using IE Mode we recommend roaming the %LocalAppData%\Microsoft\Edge\User Data\EmieSiteList.xml file and the standard settings for Internet Explorer.

Roaming the %LocalAppData%\Microsoft\Edge\User Data\Default\DualEngine folder will cause issues over time depending on how much IE Mode is used so this is not recommended.

Finally, since Edge Chromium uses Internet Explorer to deliver the IE Mode experience all the cookies, browsing history, temporary internet files, DOM store data etc. generated are stored in the same manner as when using Internet Explorer directly, so using the same roaming definitions as before will continue to give the best possible results.

VMware DEM

For VMware DEM there is a built-in “Windows Settings” for this called “IE Cookies and History”:

Ivanti EM

With Ivanti Environment Manager the built-in Windows Personalization settings can be used:

Citrix UPM

When using UPM the webcache can be handled using the “Folders to mirror” policy as per https://support.citrix.com/article/CTX224498:

Note: A quick note here that webcache and the associated data cannot be roamed between the more recent server and desktop operating systems, so it is advised to keep this separate in heterogenous deployments with both Windows 10 and Server 2016 for example.

Closing Words

The first time Edge Chromium is launched, navigating to a site listed in the Enterprise Mode site list it can fail to invoke IE Mode as expected.  It appears that the behaviour is similar to that listed in this article for Internet Explorer - https://docs.microsoft.com/en-us/internet-explorer/ie11-deploy-guide/turn-on-enterprise-mode-and-use-a-site-list, where it says “Approximately 65 seconds after Internet Explorer 11 starts, it looks for a properly formatted site list.”  The EMIESiteList.xml is not downloaded until about a minute after the browser is first launched.

When using the roaming rules recommended above the time taken for Edge Chromium to recognise and honour the Enterprise Mode site list was reduced but we did see a few instances where it took a few attempts for URL’s to trigger IE mode mostly when navigating from one IE Mode tab to another using the URL bar to manually enter the addresses.

Maybe this will get more robust with upcoming releases.

Peter Jones