Failed to resolve UnityEngine.XR.XRSettings

Hi,
I just downgrade from beta 2017.2.0b9 to stable 2017.1.0f3 . When i try to build i got this error.

Failed running /Applications/Unity/Unity.app/Contents/il2cpp/build/UnityLinker.exe --api=NET_2_0_Subset -out="/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/Managed/tempStrip" -l=none -c=link --link-symbols -x="/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Core.xml" -f="/Applications/Unity/Unity.app/Contents/il2cpp/LinkerDescriptors" -x "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/methods_pointedto_by_uievents.xml" -x "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/preserved_derived_types.xml" -x "/Applications/Unity/Unity.app/Contents/il2cpp/LinkerDescriptors/mscorlib_mono.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/AI.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Animation.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Audio.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Cloth.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Core.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/CrashReporting.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Director.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/GameCenter.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/IMGUI.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/ImageConversion.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Input.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/JSONSerialize.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/ParticleSystem.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/ParticlesLegacy.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/PerformanceReporting.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Physics.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Physics2D.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/ScreenCapture.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/SpriteMask.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/StyleSheets.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Terrain.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/TerrainPhysics.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/TextRendering.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UI.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UIElements.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UNET.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityAnalytics.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityConnect.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityWebRequest.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityWebRequestAudio.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityWebRequestTexture.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/UnityWebRequestWWW.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/VR.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Vehicles.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Video.xml" -x "/Applications/Unity/PlaybackEngines/AndroidPlayer/Whitelists/Web.xml" -x "/Users/Fatih/Documents/Ringo/Assets/Plugins/UnityPurchasing/script/link.xml" -d "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/Managed" -a  "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/Managed/Assembly-CSharp-firstpass.dll" -a  "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/Managed/Assembly-CSharp.dll" -a  "/Users/Fatih/Documents/Ringo/Temp/StagingArea/Data/Managed/UnityEngine.Analytics.dll"

stdout:
Fatal error in Unity CIL Linker
Mono.Cecil.ResolutionException: Failed to resolve UnityEngine.XR.XRSettings
  at UnityLinker.AddUnresolvedStubsStep.Process () [0x000ab] in <8faa3831367147a5b4f1efc161d11bdf>:0 
  at Mono.Linker.Steps.BaseStep.Process (Mono.Linker.LinkContext context) [0x00018] in <114d8887b0b545308ed79d49a500b4cd>:0 
  at Mono.Linker.Pipeline.Process (Mono.Linker.LinkContext context) [0x00025] in <114d8887b0b545308ed79d49a500b4cd>:0 
  at UnityLinker.UnityDriver.Run () [0x00087] in <8faa3831367147a5b4f1efc161d11bdf>:0 
  at UnityLinker.UnityDriver.RunDriverWithoutErrorHandling () [0x00001] in <8faa3831367147a5b4f1efc161d11bdf>:0 
  at UnityLinker.UnityDriver.RunDriver () [0x00002] in <8faa3831367147a5b4f1efc161d11bdf>:0 
stderr:

UnityEngine.Debug:LogError(Object)
UnityEditorInternal.Runner:RunProgram(Program, String, String, String, CompilerOutputParserBase) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:128)
UnityEditorInternal.Runner:RunManagedProgram(String, String, String, CompilerOutputParserBase, Action`1) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:73)
UnityEditorInternal.AssemblyStripper:RunAssemblyLinker(IEnumerable`1, String&, String&, String, String) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/AssemblyStripper.cs:89)
UnityEditorInternal.AssemblyStripper:StripAssembliesTo(String[], String[], String, String, String&, String&, String, IIl2CppPlatformProvider, IEnumerable`1) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/AssemblyStripper.cs:82)
UnityEditorInternal.AssemblyStripper:RunAssemblyStripper(String, IEnumerable, String, String[], String[], String, IIl2CppPlatformProvider, RuntimeClassRegistry) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/AssemblyStripper.cs:200)
UnityEditorInternal.AssemblyStripper:StripAssemblies(String, IIl2CppPlatformProvider, RuntimeClassRegistry) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/AssemblyStripper.cs:114)
UnityEditorInternal.AssemblyStripper:InvokeFromBuildPlayer(BuildTarget, RuntimeClassRegistry) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/AssemblyStripper.cs:294)
UnityEditor.HostView:OnGUI()

Had this issue downgrading from 2017.2 to 5.6, solution was explicitly reimporting the UnityPurchasing lib, under the Services tab. (Disabling and re-enabling it did NOT work).

I also downgraded and I’m getting the exact same issue.
Did you find a fix?