Here is the simple way to solve this issue "User canceled out of save dialog". Close the Visual Studio and open as Administrator.
After I cleared the cache, I was able to download the NuGet package API into my asp.net core project.
Procedure to create repository pattern ASP.net core web API get, post, patch, delete operations using Entity framework core and SQL server as database.
solution for this issue was very simple & most of the issues which will occur during debugging the application or running the application in VS
Issue while running the Visual Studio 2019 with the project created in ASP.NET Core in C# language. The solution of this problem given here.