May 25, 2020 · When I build my application I get the following error. Error CS0579 Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute MyUIApp. The following …

Feb 27, 2024 · Open the project file using a text editor and look for the GenerateAssemblyInfo property. If it is there and set to true then set it to false. Thanks a lot Michael. I've just done that and it seems …

May 16, 2025 · I have a hypothesis that a pre-release version of the C# extension had a bug that caused those files to be created as a side effect of some feature work that released recently.

Nov 25, 2025 · If you’ve worked with .NET Core 3.1, you may have encountered the frustrating build error CS0579: Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute.

Apr 23, 2022 · On a recent project I got the "CS0579 Duplicate 'global::System.Runtime.Versioning.<type>Attribute" error when I tried to build more project.

Sep 15, 2021 · Duplicate 'attribute' attribute It is not possible to specify the same attribute more than once unless the attribute specifies AllowMultiple=true in its AttributeUsage.

May 29, 2020 · What is going on here is that source files (for example the file that contains the TargetFrameworkAttribute) are generated under the BaseIntermediateOutputPath. The default …

Feb 4, 2024 · Doing a build from Visual Studio could cause multiple files to occur. Note that you should never compile from Visual Studio.

In this article, we will discuss the causes of duplicate ‘global::System.Runtime.Versioning.TargetFrameworkAttribute’ attributes, the problems they can …

For .net core (new SDK fprmat) project, it doesn't contain the AssemblyInfo.cs file by default like .net framework (old legacy format). Instead we can set those values in its project file, and it will generate …