Upgrade existing class library to .NET Core 3.0

When we are upgrading our existing class library to the latest .NET Core, like this: <TargetFramework netcoreapp3.0</TargetFramework On doing so, you may get the following warning: C:\\Program Files\\dotnet\\sdk\\3.0.000\\Sdks\\Microsoft.NET.Sdk\\targets Microsoft.NET.Sdk.Default...