Steps to reproduce:

1. Create a new project
2. Switch platform to UWP 10
3. Make sure UWP SDK is 10.0.15063 or newer
4. Build & Run

Actual result: Editor successfully builds the player, but doesn't run it (an Exception is thrown in the console)
Expected result: Editor successfully builds AND runs the built player

Reproducible with: 5.5.4p5, 5.5.5f1

Not reproducible with UWP SDK 10.0.14393

Exception: Failed to build Visual Studio project using arguments 'C:\Program Files (x86)\MSBuild\14.0\Bin\MSBuild.exe "D:\DOWNLOADS\WSA RAT\another one\WSA RAT.sln" /nologo /maxcpucount /p:Configuration=Master /p:Platform=x86 /p:SolutionDir="D:\\DOWNLOADS\\WSA RAT\\another one\\" /t:Build /clp:Verbosity=minimal'.
Output:D:\DOWNLOADS\WSA RAT\another one\WSA RAT\WSA RAT.csproj : XamlCompiler error WMC1006: Cannot resolve Assembly or Windows Metadata file 'Windows.Foundation.UniversalApiContract.winmd'
C:\Program Files (x86)\MSBuild\Microsoft\WindowsXaml\v14.0\8.2\Microsoft.Windows.UI.Xaml.Common.targets(264,5): Xaml Internal Error error WMC9999: Type universe cannot resolve assembly: Windows.Foundation.UniversalApiContract, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null, ContentType=WindowsRuntime. [D:\DOWNLOADS\WSA RAT\another one\WSA RAT\WSA RAT.csproj]

ApplicationLauncherImpl.RunMSBuild (System.String args) (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ApplicationLauncher.cs:365)
ApplicationLauncherImpl.Build () (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ApplicationLauncher.cs:220)
ApplicationLauncher.BuildAndRunOnSingle (BuildLaunchPlayerArgs args, WSASDK wsaSDK, WSABuildAndRunDeployTarget deployTarget) (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ApplicationLauncher.cs:60)
ApplicationLauncher.BuildAndRun (BuildLaunchPlayerArgs args) (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ApplicationLauncher.cs:50)
UnityEditor.WSA.BuildPostprocessor.LaunchPlayer (BuildLaunchPlayerArgs args) (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ExtensionModule.cs:121)
UnityEditor.PostprocessBuildPlayer.Launch (BuildTarget target, System.String path, System.String productName, BuildOptions options) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:150)
UnityEditor.HostView:OnGUI()