Method 1: Extract from the Original Windows Server ISO (Recommended)

/Source : Points directly to the location of the .cab package.

After installation completes (progress bar 100%), verify success:

While the exact 2012 R2 CAB is no longer prominently featured, for newer OS versions the official catalog ( catalog.update.microsoft.com ) provides similar packages. For Server 2012 R2, always fall back to the installation ISO as the trusted source.

The microsoft-windows-netfx3-ondemand-package.cab file itself is provided by Microsoft in the traditional sense; it is a component of the operating system media.

The deployment metadata exists, but the payload binary ( microsoft-windows-netfx3-ondemand-package.cab ) is missing from the local C:\Windows\WinSxS directory.

This includes:

This comprehensive guide explains why this file is missing, how to securely acquire it, and the exact step-by-step methods to deploy it using Deployment Image Servicing and Management (DISM) or PowerShell. The Problem: Why Windows Server 2012 R2 Needs the CAB File

Practical Commands (concise)

When servers point to a local Windows Server Update Services (WSUS) server for security patches, the server attempts to pull the missing component from WSUS. WSUS does not host Feature on Demand (FoD) packages by default, resulting in immediate installation failure.

Microsoft-Windows-NetFx3-OnDemand-Package~31bf3856ad364e35~amd64~~.cab Windows Server 2012 R2

You can also point to the folder containing the CAB: