ZCM 20.3 will now officially require Microsoft .NET 4.8 or later to be installed from the previous requirement of 4.5 or later.

Since .NET is a  Microsoft and not a Micro Focus product, the Official Documentation will not go into great detail beyond the requirement for .NET 4.8.  Below I will cover some important details below around which Operating Systems will already have it based on their patch level, which devices may need it, and what may need to be done to install it. 

Caveat: Keep in mind, the information below is based on links from Microsoft and as well as some personal testing.  This should not be considered the final authority, as there could be details I have not yet discovered.

https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/versions-and-dependencies#net-framework-48 will provide many details.

In short, Windows 10 1903 or later should ship with .NET 4.8 Preinstalled by default. 

Windows 7, Windows 8.1, and Windows 1607 or later support Upgrading to .NET 4.8.  All of these operating systems should automatically upgrade to .NET 4.8 if the May 2019 Cumulative Update or later is applied if .NET is installed.

Windows Server 2022 will ship with .NET 4.8 Installed.

Windows Server 2008R2 SP1 thru 2019 will support upgrading to .NET 4.8.  (Note: Even Windows Server 2019 Media Refreshed in 2021 does not appear to include .NET 4.8).  Unlike the client operating systems above, applying cumulative updates does not appear to upgrade the .NET version.  This holds true for my testing on Windows 2016 and Windows 2019 Server OS.

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How do I upgrade my systems to .NET 4.8?

For Client Operating Systems, that should be simple.  Simply ensure you have applied the required cumulative updates for the operating system.

For Server OS,

Windows Server 2019 ->  See https://support.microsoft.com/en-us/topic/microsoft-net-framework-4-8-on-windows-10-version-1709-windows-10-version-1803-windows-10-version-1809-and-windows-server-2019-9e61c44e-08d2-f20d-c890-9ed873d9dba0

Try Applying the following - https://www.catalog.update.microsoft.com/Search.aspx?q=KB4486153  -  (Note: The MSU in the catalog may work better than the offline installer for Non-English Language Systems.)

Windows Server 2016 -> See https://support.microsoft.com/en-us/topic/microsoft-net-framework-4-8-for-windows-10-version-1607-windows-10-version-1703-and-windows-server-2016-8ff8f85c-65f8-8fae-b85a-c556efce33fd -

Try Applying the following -> https://www.catalog.update.microsoft.com/Search.aspx?q=kb4486129  - (Note: The MSU in the catalog may work better than the offline installer for Non-English Language Systems.)

For Windows Server Versions older than 2016, I would simply suggest referring to MS Docs.  I no longer have any such systems in my lab and do not intend to install them simply for verifying MS documentation.

One way to manually verify the installed .NET Version can be found here.

https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/how-to-determine-which-versions-are-installed

"Version" under Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full will easily confirm the .NET is 4.8 or greater.

"Release" has the more exact value and the doc above can help decipher the value.

Note: Both the ZENworks Agent installer, as well as the ZENworks 20.3 System Update, will try to install .NET 4.8 if required using the .NET 4.8 offline installer.  In some cases, however, the generic .NET 4.8 Installer may fail to install necessitating the specific MSU for that OS.  This has been reported most often if non-English .NET Language Packs are installed.  As a reminder, .NET and its installers and updates are Microsoft Products and not Micro Focus.