In this article, we examine why roaming user profiles in Windows 10 and Windows Server are incompatible with Roaming user profiles in earlier versions of Windows. We will also provide recommendations to help resolve this issue.
Roaming user profiles are incompatible
When you try to deploy Windows 10 in an environment that uses roaming profiles in Windows 7, you experience the following behavior:
After using a user account with an existing Windows 7 or Windows 8.1 profile to sign in to a Windows 10 computer for the first time, Windows 10 components read and change the state of the profile. Also, cSome features of Windows 7, Windows 8.1 or Windows 10 may not work as expected because the expected profile status is not present. For example, the Start menu does not start. Cortana, the taskbar is not responding. And the taskbar icons are missing.
Also, when you try to use the same user account to log in to a Windows 7 computer, the user profile change that was made in Windows 10 may not work as expected in Windows 7 or Windows 8.1.
Causes roaming user profile version mismatch issues in Windows 10
By default, Windows 10 clients use a "v5”Profile folder extension. On earlier versions of Windows, the default version was "v2".
This problem is caused the first time you use a user account with a Windows 7, Windows 8, or Windows 8.1 profile to log in to a Windows 10 computer, a "v5" or "v6»The profile version is created.
To resolve this issue, Microsoft suggests that you make sure that you do not disable Profile version management.
By default, profile version management is enabled in Windows 10, Windows Server 2016 and later versions of Windows.
This behavior is by design and has been implemented due to incompatibilities between profile versions. If user accounts that use roaming profiles sign in to both Windows 10 and earlier versions of Windows, there must be a profile for each version type.
You can find more information on Mandatory profiles. here.
I hope you find this guide useful enough!