title: TeamCity NetCore 'dotnet restore' Error Value cannot be null
body: <p>I'm attempting to build and deploy a netcore app for the first time with TeamCity.  I followed the guide from <a href="https://blog.jetbrains.com/teamcity/2016/11/teamcity-dotnet-core/" rel="nofollow noreferrer">https://blog.jetbrains.com/teamcity/2016/11/teamcity-dotnet-core/</a></p>
  
  <p>I'm running into an issue where TeamCity returns a 'Exit code 1." error at the beginning of the first build step. (a dotnet restore) step.  </p>
  
  <p>In the build logs it says the following.</p>
  
  <pre><code>Step 1/3: .NET Core (dotnet)
  [15:33:58][Step 1/3] Starting: "C:\Program Files\dotnet\dotnet.exe" restore src/ProjectFolder
  [15:33:58][Step 1/3] in directory:  E:\TeamCity\buildAgent3\work\1151efaecddc7512
  [15:33:58][Step 1/3] error: Value cannot be null.
  [15:33:58][Step 1/3] error: Parameter name: path1
  [15:33:58][Step 1/3] Process exited with code 1
  [15:33:58][Step 1/3] Step .NET Core (dotnet) failed
  </code></pre>
  
  <p>I have tried reinstalling the NetCore sdk on my build agents. Among other things.  Any guidance or help would be appreciated. </p>
  
  <p>Current dotnet version is 1.0.0-preview2-1-003177.</p>