UnassignedReferenceException error on EditorUpdate in Unity 5.6

Question

Anyone else receiving this error in Unity 5.6? 

UnassignedReferenceException: The variable m_HandleRect of Slider has not been assigned.
You probably need to assign the m_HandleRect variable of the Slider script in the inspector.
UnityEngine.RectTransform.get_anchorMin () (at /Users/builduser/buildslave/unity/build/artifacts/generated/common/runtime/RectTransformBindings.gen.cs:116)
MaterialUI.MaterialSlider.OnEditorUpdate () (at Assets/MaterialUI/Scripts/Components/MaterialSlider.cs:796)
MaterialUI.EditorUpdate.Update () (at Assets/MaterialUI/Scripts/MaterialUtils/EditorUpdate.cs:48)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at /Users/builduser/buildslave/unity/build/artifacts/generated/common/editor/EditorApplicationBindings.gen.cs:249)

 

 

 

The error occurs when using MaterialUI 1.1.4 as well as 1.1.6 after a fresh import. 

Any suggestions on how to fix would be greatly appreciated. Will be downgrading back to Unity 5.5 in the meantime.

Comments

If anyone else has run into this issue in Unity 5.6, I've found that a restart of Unity will usually fix the issue.