The target "AddUmbracoFilesToOutput" does not exist in the project.
Visual Studio 2019 Üzerinde belirtilen dosyanın içerisine. * burada sizin profilinize göre değişebilir. Ben Folder publish almıştım o nedenle FolderProfile.pubxml olarak geçiyordu. Project node içerisine aşağıdaki kodu yerleştirdiğinizde sorun gidecektir.
Properties > PublishProfiles > *Profile.pubxml
<Target Name="AddUmbracoFilesToOutput">
<!-- With help from: http://blog.samstephens.co.nz/2010-10-18/msbuild-including-extra-files-multiple-builds/ -->
<ItemGroup>
<CustomFilesToInclude Include=".\App_Browsers\**\*">
<Dir>App_Browsers</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\App_Code\**\*">
<Dir>App_Code</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\App_Plugins\**\*">
<Dir>App_Plugins</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\bin\amd64\**\*">
<Dir>bin\amd64</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\bin\x86\**\*">
<Dir>bin\x86</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\Config\Splashes\**\*">
<Dir>Config\Splashes</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\data\**\*">
<Dir>data</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\umbraco\**\*">
<Dir>umbraco</Dir>
</CustomFilesToInclude>
<CustomFilesToInclude Include=".\Global.asax">
<Dir>.</Dir>
</CustomFilesToInclude>
<FilesForPackagingFromProject Include="@(CustomFilesToInclude)">
<DestinationRelativePath>%(CustomFilesToInclude.Dir)\%(RecursiveDir)%(Filename)%(Extension)</DestinationRelativePath>
</FilesForPackagingFromProject>
</ItemGroup>
</Target>