vscode-csharp: Failure with .NET Core 2.0.0-preview2 SDK

From @cesarbs on May 18, 2017 17:18

Got this in VS Code with the latest pre-release version of the C# extension (1.10.0-beta3):

[fail]: OmniSharp.MSBuild.ProjectFile.ProjectFileInfo
        The "ResolvePackageDependencies" task failed unexpectedly.
This is an unhandled exception from a task -- PLEASE OPEN A BUG AGAINST THE TASK OWNER.
System.TypeLoadException: Could not resolve type with token 01000040
  at Microsoft.NET.Build.Tasks.ResolvePackageDependencies.GetPackageAndFileDependencies (NuGet.ProjectModel.LockFileTarget target) [0x0011f] in <9445a2665fcc4f009bbfa9fcd34c78f9>:0 
  at Microsoft.NET.Build.Tasks.ResolvePackageDependencies.RaiseLockFileTargets () [0x000a6] in <9445a2665fcc4f009bbfa9fcd34c78f9>:0 
  at Microsoft.NET.Build.Tasks.ResolvePackageDependencies.ExecuteCore () [0x00006] in <9445a2665fcc4f009bbfa9fcd34c78f9>:0 
  at Microsoft.NET.Build.Tasks.TaskBase.Execute () [0x00000] in <9445a2665fcc4f009bbfa9fcd34c78f9>:0 
  at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute () [0x0002a] in <6a1392588f4a45bdbe07807130f9b3d0>:0 
  at Microsoft.Build.BackEnd.TaskBuilder+<ExecuteInstantiatedTask>d__26.MoveNext () [0x002bf] in <6a1392588f4a45bdbe07807130f9b3d0>:0 
[warn]: OmniSharp.MSBuild.MSBuildProjectSystem
        Failed to load project file '/Users/Cesar/src/aspnet/KestrelHttpServer/src/Microsoft.AspNetCore.Server.Kestrel.Core/Microsoft.AspNetCore.Server.Kestrel.Core.csproj'.
/Users/Cesar/src/aspnet/KestrelHttpServer/src/Microsoft.AspNetCore.Server.Kestrel.Core/Microsoft.AspNetCore.Server.Kestrel.Core.csproj

Happens on every project in Kestrel.

dotnet info:

$ dotnet --info
.NET Command Line Tools (2.0.0-preview2-006082)

Product Information:
 Version:            2.0.0-preview2-006082
 Commit SHA-1 hash:  6453cb4e15

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.12
 OS Platform: Darwin
 RID:         osx.10.12-x64
 Base Path:   /Users/Cesar/.dotnet/sdk/2.0.0-preview2-006082/

Microsoft .NET Core Shared Framework Host

  Version  : 2.0.0-preview2-25309-07
  Build    : 41f5fc94eedc889f086800c23f35bf14a8c75a9f

Copied from original issue: dotnet/sdk#1229