When working with the new feature pack feature related to auto build and deployment, you can get the following error in the deployment phase:
2017-11-02T08:25:50.9704669Z ##[error]Cannot validate argument on parameter ‘PackagePath’. The ” Test-Path -Path $_ -PathType ‘Leaf’ ” validation script for the argument with value “your path” did not return a result of True. Determine why the validation script failed, and then try the command again.
As it is stated in the official BizTalk Server documentation here: https://docs.microsoft.com/en-us/biztalk/core/add-a-biztalk-server-application-to-visual-studio-team-services a new application project should be added to your BizTalk Server solution (BizTalk Server Application Project (.btaproj).)
However, it might happen that when you try to add this new kind of project it is not available. This is because Visual Studio is not targeting the right .NET Framework version for this new BizTalk Server feature (required >= 4.61)
Now the new project will become available and after you set up the all properties as per the previous referenced documentation, everything should run smoothly: