2
votes

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?

1
Yes, I tried to open in VS2017 and its opened but vs2017 is doesn't have .net framework 4.6.1. I need framework 4.6.1.Saritha Gangareddy
If it need .net framework 4.6.1, you can download from following link:microsoft.com/net/download/thank-you/net461?survey=false. Besides, if the answer resolve your question, you can Accept it as an Answer, This can be beneficial to other community members reading this thread.Leo Liu-MSFT
Thank you for comments, I installed .net framework 4.5.2 and 4.6.1 also but when I am checking in application the target framework its not showing anything in dropdownlist in VS2017.Saritha Gangareddy
Could you successfully create a new blank project in VS2017 with .net framework 4.6.1? If yes, this issue should be more related to your project, you can share the project file to us, open the .csproj/vcxproj file with notepad.Leo Liu-MSFT
Again, if your project is a multi-targeting project, like, <TargetFrameworks>netcoreapp2.0;net461</TargetFrameworks> in your project file, the target framework should not show anything.Leo Liu-MSFT

1 Answers

2
votes

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:

enter image description here

So please try to open it with Visual Studio 2017.

See similar issue for some more details.