Removed Framework wise NuGet package for Syncfusion ASP.NET CORE (Essential JS 1) platform – v16.1600.0.xx
Starting from version 16.1.0.24, Syncfusion® has updated the structure of the ASP.NET Core (Essential JS1) NuGet packages. This includes changes to how frameworks are grouped and how package versions are managed.
As a result of this restructuring, when installing or updating the Syncfusion® ASP.NET Core package using the Syncfusion® private NuGet server feed
(https://nuget.syncfusion.com/nuget_aspnetcore/nuget/getsyncfusionpackages/aspnetcore), the latest stable version is always displayed as 16.1600.*.* in the Visual Studio NuGet Package Manager.
Please refer to the screenshot below for a visual reference.

The latest stable version is wrongly displayed as the issue, due to the Syncfusion® ASP.NET Core package versions being ordered by numeric value (1600>2) and its default behavior in NuGet.
As a result of the updated package structure, the framework-based NuGet packages for Syncfusion® ASP.NET Core v16.1.0.xx (specifically versions 16.1600.0.24, 16.1600.0.26, and 16.1600.0.32) have been removed from the Syncfusion® private NuGet server. Instead, framework-grouped packages have been provided for these versions, offering a more streamlined and consistent experience. You can find detailed information about the framework-grouped Syncfusion.AspNet.Core packages here.
You will face the unable to find package issue when restoring the solution or project if still using the NuGet package version with Framework (eg., 16.1600.0.xx).

If you install the 16.1600.0.xx release version of Syncfusion® ASP.NET Core NuGet packages in your application and want to update your Syncfusion® ASP.NET Core (Essential JS 1) packages, and then update the required Syncfusion® ASP.NET Core (Essential JS 1) packages in one of the following ways:
Package Manager
Update the Syncfusion® ASP.NET Core (Essential JS 1) packages by choosing the required version from the NuGet Package Manager drop-down manually.
Package Manager Console
You can update the Syncfusion® ASP.NET Core packages by Package Manager console with required version.
> Update-Package <package id> -Version <version>