This article provides a detailed walkthrough: what the .NET Framework 4.8 is, why you need the offline installer specifically for Server 2016, how to obtain it legitimately, step-by-step installation instructions, troubleshooting tips, and answers to frequently asked questions.
.net 4.8 fails installation on 2016 windows server - Microsoft Q&A .net framework 4.8 offline installer for windows server 2016