问题
I am trying to add an existing project to my source project in VS2015, and I am getting the following error:
Visual Studio 2015 - The default XML namespace of the project must be the MSBuild XML namespace. If the project is authored in the MSBuild 2003 format, please add xmlns="http://schemas.microsoft.com/developer/msbuild/2003" to the element. if the project has been authored in the old 1.0 or 1.2 format, please convert it to MSBuild 2003 fromat.
How can I solve this?
回答1:
VS2015-The default XML namespace of the project must be the MSBuild XML namespace.
You may open the new .Net Core csproj format with Visual Studio 2015, you should use Visual Studio 2017 which supports this new format to open your project.
To test it, I created a .net core project with Visual Studio 2017, then open it with Visual Studio 2015, then I got the same error with you:
So please try to open it with Visual Studio 2017.
See similar issue for some more details.
来源：https://stackoverflow.com/questions/49107742/vs2015-the-default-xml-namespace-of-the-project-must-be-the-msbuild-xml-namespac