while coding csharp i get the error : "Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute [first_better_project]"

Code Example - while coding csharp i get the error : "Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute [first_better_project]"

                
                        <GenerateTargetFrameworkAttribute>false</GenerateTargetFrameworkAttribute>