Problem Generating Build on Mac with Unity 5.6

ArgumentOutOfRangeException: startIndex + length > this.length
Parameter name: length
System.String.Substring (Int32 startIndex, Int32 length) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/String.cs:356)
I2.Loc.LanguageSource.GetLanguagesCode (Boolean allowRegions, Boolean skipDisabled) (at Assets/I2/Localization/Scripts/LanguageSource.cs:382)
I2.Loc.LocalizationManager.GetAllLanguagesCode (Boolean allowRegions, Boolean SkipDisabled) (at Assets/I2/Localization/Scripts/LocalizationManager.cs:667)
I2.Loc.PostProcessBuild_IOS.ChangeXcodePlist (BuildTarget buildTarget, System.String pathToBuiltProject) (at Assets/I2/Localization/Scripts/Editor/PostProcessBuild_IOS.cs:21)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.Build.BuildPipelineInterfaces+AttributeCallbackWrapper.OnPostprocessBuild (BuildTarget target, System.String path) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:65)
UnityEditor.Build.BuildPipelineInterfaces.OnBuildPostProcess (BuildTarget platform, System.String path, Boolean strict) (at /Users/builduser/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:274)
UnityEditor.HostView:OnGUI()