Publishing with Visual Studio 2017 MVC ASP.NET Core "They must have the same number of items"

Question

I get the following message when I try and Publish:

Severity Code Description Project File Line Suppression State

Error "DestinationFiles" refers to 1 item(s), and "SourceFiles" refers to 2 item(s). They must have the same number of items.

I have my project working on my localhost and I am now looking to publish...but I get the above error. I converted my project from VS 2015 and Publishing was working fine. Just to make sure my old Publishing Profile wasn't the issue , I deleted my old working copy of my Profile and set up a new one. I know that VS 2017 was just released a couple of days ago, any help would be great.

Answer 1

I think there is a bug in the Microsoft.NET.Publish.targets file.

I changed the DestinationFiles line (line 99 and 127) as below, and now it works

<Copy SourceFiles = "@(_ResolvedFileToPublishAlways)"
      DestinationFiles="@(_ResolvedFileToPublishAlways -> '$(PublishDir)%(RelativePath)')"
      OverwriteReadOnlyFiles="$(OverwriteReadOnlyFiles)"
      Retries="$(CopyRetryCount)"
      RetryDelayMilliseconds="$(CopyRetryDelayMilliseconds)"
      UseHardlinksIfPossible="$(CreateHardLinksForPublishFilesIfPossible)"
      UseSymboliclinksIfPossible="$(CreateSymbolicLinksForPublishFilesIfPossible)">

Answer 2

This is a known bug and is mentioned in the VS2017 RC Tooling Known Issues document:

Unable to publish

Unable to publish ASP.NET Core Web Application (.NET Framework)

• Issue:

If you try to publish an ASP.NET Core Web Application (.NET Framework), you will run into the following error: "DestinationFiles" refers to 1 item(s), and "SourceFiles" refers to 2 item(s). They must have the same number of items

• Workaround:

None available

https://github.com/aspnet/Tooling/blob/master/known-issues-vs2017.md

Look back later to see if a workaround is provided.

Editing "Microsoft.NET.Publish.targets" in folder "C:\Program Files\dotnet\sdk\1.0.0-preview4-004233\Sdks\Microsoft.NET.Sdk\build" didn't work for me though.