.NET Core 3.1 was made available to the public at December 3, 2019. It aims to support C# 8.0, F# 4.7, building Windows Desktop applications, Single-file executables, fast built-in JSON support, and more. You can access the changelogs for all the patches for .NET Core 3.1 here.
Let’s get straight to the point.
Two months ago, Microsoft have recently announced the end of support date for .NET Core 3.1 on their developer blog post. After exactly three months, which we’ll make it December 13th, 2022, Microsoft will no longer support .NET Core 3.1. This means that there will be no more technical support and quality updates for .NET Core 3.1.
Also, Microsoft have suggested that “every security fix in .NET 6 after the end of support date is a potential documented and unpatched security vulnerability for .NET Core 3.1 apps.”
Impact to us
We’ll stop supplying .NET Core 3.1 targeted versions of our libraries. This means that there will be no more netcoreapp3.1 folder in the build output. However, we’re working on porting all our libraries to .NET Standard 2.1 + .NET Framework 4.8 combo.
Upgrading
To upgrade your project to .NET 6.0, open the project file on your favorite text editor (Visual Studio Code, Sublime Text, Vim, etc.) or even Visual Studio itself, and change the value of TargetFramework from netcoreapp3.1 to net6.0. There may be breaking changes, so satisfy all of them using appropriate alternatives.
You can download .NET 6.0 by clicking on the button below:
Aptivi 
Thoughts?