Steps to reproduce:
1. Download attached project
2. Attempt to build and run to WP8 platform. It will fail with Assembly Converter exception:
Exception: Failed to run assembly converter with command line -platform=wp80 "Temp/StagingArea\Assembly-CSharp.dll" "Temp/StagingArea\UnityEngine.dll" "Temp/StagingArea\UnityEngine.UI.dll" "Temp/StagingArea\WinRTLegacy.dll".
System.ArgumentException: Member 'System.Void System.ArgumentOutOfRangeException::.ctor(System.String)' is declared in another module and needs to be imported
at Mono.Cecil.MetadataBuilder.LookupToken(IMetadataTokenProvider provider)
at Mono.Cecil.Cil.CodeWriter.WriteOperand(Instruction instruction)
at Mono.Cecil.Cil.CodeWriter.WriteInstructions()
at Mono.Cecil.Cil.CodeWriter.WriteResolvedMethodBody(MethodDefinition method)
at Mono.Cecil.Cil.CodeWriter.WriteMethodBody(MethodDefinition method)
at Mono.Cecil.MetadataBuilder.AddMethod(MethodDefinition method)
at Mono.Cecil.MetadataBuilder.AddMethods(TypeDefinition type)
at Mono.Cecil.MetadataBuilder.AddType(TypeDefinition type)
at Mono.Cecil.MetadataBuilder.AddTypeDefs()
at Mono.Cecil.MetadataBuilder.BuildTypes()
at Mono.Cecil.MetadataBuilder.BuildModule()
at Mono.Cecil.ModuleWriter.<BuildMetadata>b__0(MetadataBuilder builder, MetadataReader _)
at Mono.Cecil.ModuleDefinition.Read[TItem,TRet](TItem item, Func`3 read)
at Mono.Cecil.ModuleWriter.BuildMetadata(ModuleDefinition module, MetadataBuilder metadata)
at Mono.Cecil.ModuleWriter.WriteModuleTo(ModuleDefinition module, Stream stream, WriterParameters parameters)
at Mono.Cecil.ModuleDefinition.Write(Stream stream, WriterParameters parameters)
at Mono.Cecil.ModuleDefinition.Write(String fileName, WriterParameters parameters)
at Unity.SaveModulesStep.ProcessModule()
at Unity.ModuleStep.Execute()
at Unity.Step.Execute(OperationContext operationContext, IStepContext previousStepContext)
at Unity.Operation.Execute()
at Unity.Program.Main(String[] args)

PostProcessWP8Player.ConvertAssemblies (System.String stagingArea, System.String playerPackage, .LibraryCollection libraries) (at C:/buildslave/unity/build/PlatformDependent/WP8Player/Extensions/Managed/PostProcessWP8Player.cs:351)
PostProcessWP8Player.PostProcess (BuildTarget target, BuildOptions options, System.String installPath, System.String stagingArea, System.String playerPackage, System.String companyName, System.String productName, Guid productGUID) (at C:/buildslave/unity/build/PlatformDependent/WP8Player/Extensions/Managed/PostProcessWP8Player.cs:213)
UnityEditor.WP8.BuildPostprocessor.PostProcess (BuildPostProcessArgs args) (at C:/buildslave/unity/build/PlatformDependent/WP8Player/Extensions/Managed/ExtensionModule.cs:103)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, System.String downloadWebplayerUrl, System.String manualDownloadWebplayerUrl, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:316)
UnityEditor.HostView:OnGUI()