The standalone redistributable ( .msi ) named “Microsoft Report Viewer 2016 Runtime” includes version 12.0.0.0. You can find it under the SQL Server 2016 Feature Pack on Microsoft’s official download center (if still available).
He hovered over the link. The details pane confirmed it: Version: 12.0.2000.8 . This was the one. This package contained the elusive Microsoft.ReportViewer.WebForms.dll and Microsoft.ReportViewer.Common.dll that his application was screaming for. microsoft report viewer version 12.0.0.0 download