Error CS0122: inaccessable due to protection level

Questions & Answers
1

I’ve had no problem with this script until yesterday, I’m fairly new to coding, but I’ve gone through this several times and can’t find the problem? The full error is

Assets/Editor/ImageEffects/CreaseShadingEditor.cs(8,23): error CS0122: `CreaseShading’ is inaccessible due to its protection level

But I can’t find an issue on line 8 or anywhere else? Am I just being dim?

using System;
using UnityEditor;
using UnityEditor.AnimatedValues;
using UnityEngine;

namespace UnityStandardAssets.ImageEffects
{
	[CustomEditor(typeof(CreaseShading))]
    class CreaseShadingEditor : Editor {
        SerializedObject serObj;

        SerializedProperty m_intensity;
		SerializedProperty m_softness;
		SerializedProperty m_spread;

        AnimBool m_showSoftnessWarning = new AnimBool();
        AnimBool m_showSpreadWarning = new AnimBool();

        bool softnessWarningValue { get { return m_softness.intValue > 4; } }
		bool spreadWarningValue { get { return m_spread.floatValue > 4; } }

        void OnEnable () {
            serObj = new SerializedObject (target);

            m_intensity = serObj.FindProperty("intensity");
            m_softness = serObj.FindProperty("softness");
            m_spread = serObj.FindProperty("spread");

            m_showSoftnessWarning.valueChanged.AddListener(Repaint);
            m_showSpreadWarning.valueChanged.AddListener(Repaint);

            m_showSoftnessWarning.value = softnessWarningValue;
            m_showSpreadWarning.value = spreadWarningValue;
        }

        public override void OnInspectorGUI () {
            serObj.Update ();

            EditorGUILayout.Slider(m_intensity, -5.0f, 5.0f, new GUIContent("Intensity"));

            EditorGUILayout.IntSlider(m_softness, 0, 15, new GUIContent("Softness"));
            m_showSoftnessWarning.target = softnessWarningValue;
            if (EditorGUILayout.BeginFadeGroup(m_showSoftnessWarning.faded))
            {
                EditorGUILayout.HelpBox("High Softness value might reduce performance.", MessageType.Warning, false);
            }
            EditorGUILayout.EndFadeGroup();

            EditorGUILayout.Slider(m_spread, 0.0f, 50.0f, new GUIContent("Spread"));
            m_showSpreadWarning.target = spreadWarningValue;
            if (EditorGUILayout.BeginFadeGroup(m_showSpreadWarning.faded))
            {
                EditorGUILayout.HelpBox("High Spread value might introduce visual artifacts.", MessageType.Warning, false);
            }
            EditorGUILayout.EndFadeGroup();

            serObj.ApplyModifiedProperties ();
        }
    }
}
2

It tells you that CreaseShading can’t be used because it’s either private or protected, thus inaccessible.
I guess this class is declared public though. Is CreaseShading declared in the same namespace?