I am currently testing Horizon 2103 with a Window 10 1909 image.  Office 2016 is installed on the image.  I am also using DEM.

The issue I am having is that I cannot launch Outlook.  Depending on whether or not Cached Mode is enabled gives me a different error.

With Cached Mode off, I get this error:

Cannot start Microsoft Outlook.  Cannot open the Outlook window.  The set of folders cannot be opened.  The attempt to logon to Microsoft Exchange has failed.

With Cached Mode on and not redirecting the OST:

Cannot start Microsoft Outlook.  Cannot open the Outlook window.  The set of folders cannot be opened. Your profile is not configured.

With Cached Mode on and redirecting the OST to DEM User Profile share or App Volume Writable:

Cannot start Microsoft Outlook.  Cannot open the Outlook window.  The set of folders cannot be opened. The file is not an Outlook data file.

I have Googled and Googled which is why I have tried both redirecting the OST to the DEM User Profile share and also trying App Volumes Writeable Volume as those seem to be the most common solutions I found.

The funny thing is, in my lab, this works fine by just redirecting to the DEM profile.  In production, this is the problem.  My only assumption is there is a GPO in production that I don't have in the lab that is causing the problem.

Does anyone else have any other ideas of what I can do to fix this?  Would creating an App Package be a better solution or will I hit the same wall with the OST?