问题 I'm using .NET Framework 4.7, I have implemented several of syntax like this Task<(bool isSuccess, string message)> DownloadFileResource() And it already worked by getting there result with var var downloadResult = await BlobUtils.DownloadFileResource() But today when I open visual studio, all my var transform to dynamic type as a suggestion from IDE, not a (bool isSuccess, string message) anymore, and throw error when running it Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: 'System