How do I solve this error when building a project with Visual Studios 2017?

Here is the output from Visual Studios: 1>------ Build started: Project: FPS2, Configuration: Debug ARM ------ 1> FPS2 -> C:\Users\jackh\Documents\XboxTest\UWP\FPS2\bin\ARM\Debug\FPS2.exe 1> UnityWSAPlayerDir "C:\Program Files\Unity\Editor\Data\PlaybackEngines\MetroSupport\". 1> UnityProjectDir "". 1> Copying unprocessed assemblies... 1> Running AssemblyConverter... 1> System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. 1> at System.Collections.Generic.Dictionary`2.get_Item(TKey key) 1> at UnityEditor.Scripting.Compilers.NuGetPackageResolver.Resolve() 1> at Unity.UWPAssemblyResolver..ctor(String projectLockFile, String desiredUWPSDKVersion) 1> at Unity.OperationContext.SetPlatform(Platform platform, String projectLockFile, String uwpSDK) 1> at Unity.ParseArgsStep.Execute() 1> at Unity.Step.Execute(OperationContext operationContext, IStepContext previousStepContext) 1> at Unity.Operation.Execute() 1> at Unity.Program.Main(String[] args) 1>C:\Users\jackh\Documents\XboxTest\UWP\FPS2\FPS2.csproj(260,9): error MSB3073: The command ""C:\Users\jackh\Documents\XboxTest\UWP\Unity\Tools\AssemblyConverter.exe" -platform=uap -lock="C:\Users\jackh\Documents\XboxTest\UWP\FPS2\project.lock.json" -bits=32 -configuration=Debug -removeDebuggableAttribute=False -uwpsdk=10.0.15063.0 -path="." -path="C:\Program Files\Unity\Editor\Data\PlaybackEngines\MetroSupport\Players\UAP\dotnet\ARM\Debug" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\Assembly-CSharp-firstpass.dll" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\Assembly-CSharp.dll" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\UnityEngine.dll" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\nunit.framework.dll" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\UnityEngine.UI.dll" "C:\Users\jackh\Documents\XboxTest\UWP\FPS2\UnityEngine.Networking.dll"" exited with code 1. ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== ========== Deploy: 0 succeeded, 0 failed, 0 skipped ==========