title: Hololens Apps Will No Longer Build - Cites Metadata file missing and c-Sharp.firstpass not found
body: <p>I have followed the exact steps Microsoft lists under multiple projects within their <a href="https://developer.microsoft.com/en-us/windows/holographic/academy" rel="noreferrer">Microsoft Holographic - Academy</a> tutorials. I completed them all, and all of them worked just fine from creation to export and testing. This is using Unity3D / C# which gets compiled into a Visual Studio Solution (sln) file.</p>
  
  <p>After completing those, I went on to build my own app - which built just fine as well. No problem!</p>
  
  <p>Now when I try to build - I get a strange error that the c-Sharp.firstpass file (the exported/cross-compiled dll from what I understand) can not be found.</p>
  
  <p>Now even the projects that built successfully won't build any more.</p>
  
  <p>I will paste the exact error below.</p>
  
  <p>Things I have tried:</p>
  
  <ul>
  <li>Creating a new project and pasting all of the previous assets into it - then rebuilding.</li>
  <li>Cleaning the VS project</li>
  <li>Restarting my computer</li>
  <li>Restarting Unity3D</li>
  <li>Uninstalling and reinstalling Visual Studio (recommended version)</li>
  <li>Uninstalling and reinstalling Unity3D (recommended version)</li>
  <li>Following the tutorials step-by-step again</li>
  <li>Searching StackOverflow and attempting every solution whose question remotely resembled my issue</li>
  <li>Asking on Unity Answers (2 days ago)</li>
  <li>Building the project file to different drives, folders, locations, etc.</li>
  <li>To not give up</li>
  </ul>
  
  <p>There seems to be a referencing issue - so I have also unreferenced/referenced the mentioned file.</p>
  
  <p>Thanks for any and all help. To be clear, this is a Windows 10 Universal app being developed for the Microsoft Hololens. However, the device itself seems to have little to nothing to do with the build process in this case, other than targeting it.</p>
  
  <p>Best,</p>
  
  <p>Addyarb</p>
  
  <p>The error:</p>
  
  <blockquote>
    <p>The command ""D:\Development\Hololens Builds\PlanetApp\Unity\Tools\SerializationWeaver\SerializationWeaver.exe" "D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp-firstpass\bin\x86\Release\Unprocessed\Assembly-CSharp-firstpass.dll" -pdb -verbose -unity-engine="D:\Development\Hololens Builds\PlanetApp\Planetarium\Unprocessed\UnityEngine.dll" -unity-networking=D:\Development\Hololens Builds\PlanetApp\Planetarium\Unprocessed\UnityEngine.Networking.dll "D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp-firstpass\obj\x86\Release\x86\Release"" exited with code 1.  Assembly-CSharp-firstpass   D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp-firstpass\Assembly-CSharp-firstpass.csproj 180 </p>
    
    <p>Metadata file 'D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp-firstpass\bin\x86\Release\Assembly-CSharp-firstpass.dll' could not be found   Assembly-CSharp D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp\CSC    </p>
    
    <p>Metadata file 'D:\Development\Hololens Projects\Planetarium\UWP\Assembly-CSharp\bin\x86\Release\Assembly-CSharp.dll' could not be found    Planetarium D:\Development\Hololens Builds\PlanetApp\Planetarium\CSC        </p>
  </blockquote>