Subdividing a Bezier shape will result in a black mesh and errors in the console.

"ProBuilder.EditorCore.pb_Editor.OnGUI () (at /Users/karlh/procore/probuilder2/probuilder2.0/Assets/ProCore/ProBuilder/Editor/EditorCore/pb_Editor.cs:405)
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.HostView.Invoke (System.String methodName, System.Object obj) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:291)
UnityEditor.HostView.Invoke (System.String methodName) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:284)
UnityEditor.HostView.InvokeOnGUI (Rect onGUIPosition) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:251"

Steps to Reproduce
- Open the attached project using 2018.1.0b13.
- Open the "Models" scene found in the "Assets > _Scenes" folder.
- In the hierarchy select the "New Game Object".
- Open the probuilder tools menu.
- Select Subdivide object.
NOTICE ISSUE >> Errors in the console, the object in the scene turns black.