CS0012 error when building Origami (Hololens 101 tutorial)

Hello!

I have been tortured by the CS0012 error for one week (https://forums.hololens.com/discussion/10512/cs0012-error-when-trying-to-deploy-origami-hololens-101-tutorial-to-hololens#latest)

Briefly speaking, I follow the Holograms 101 tutorial (https://docs.microsoft.com/en-us/windows/mixed-reality/holograms-101). When I tried to deploy the holograms to Hololens at the end of Chapter 1, I encountered two errors and the build failed. Two errors are:

1. The type "CoreApplicationView" is defined in an assembly that is not referenced. You must add a reference to assembly "Windows, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null, ContentType=WindowsRuntime".

2. The type "CoreWindow" is defined in an assembly that is not referenced. You must add a reference to assembly "Windows, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null, ContentType=WindowsRuntime".

I have searched online for solutions but I turned out to find some same questions without a valid solution, or solutions which didn't work for me.

I'm using win10 OS, Visual Sudio Community 2017 Version 15.7.1, Unity 2017.2.0f3.

I was wondering whether the errors have something to do with Assembly-CSharp-firstpass. After generating the APP, under the dir Origami/App/GeneratedProjects/UWP there is only one folder Assembly-CSharp but no Assembly-CSharp-firstpass. I also tried to search anything related to Assembly-CSharp-firstpass under the Origami dir but there's nothing. However, I never encountered the error "Assembly-CSharp-firstpass.dll is not found" which some people reported.

Anybody has experience with this problem? Thanks a lot in advance for any help!!