Horrible Console Spam... no ideas!! PLEASE HELP!

Whats all this.. Just suddenly turned up! Any clues anyone?

TypeLoadException: Could not load type 'USHOTweenFrom' from assembly 'Assembly-CSharp, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'. UnityEditor.CustomEditor..ctor (System.Type inspectedType) System.MonoCustomAttrs.GetCustomAttributesBase (ICustomAttributeProvider obj, System.Type attributeType) (at /Users/builduser/buildslave/monoAndRuntimeClassLibs/build/mcs/class/corlib/System/MonoCustomAttrs.cs:108) System.MonoCustomAttrs.GetCustomAttributes (ICustomAttributeProvider obj, System.Type attributeType, Boolean inherit) (at /Users/builduser/buildslave/monoAndRuntimeClassLibs/build/mcs/class/corlib/System/MonoCustomAttrs.cs:151) System.MonoType.GetCustomAttributes (System.Type attributeType, Boolean inherit) (at /Users/builduser/buildslave/monoAndRuntimeClassLibs/build/mcs/class/corlib/System/MonoType.cs:595) UnityEditor.CustomEditorAttributes.Rebuild (System.Reflection.Assembly assembly) UnityEditor.CustomEditorAttributes.FindCustomEditorType (UnityEngine.Object o, Boolean multiEdit) UnityEditor.InspectorWindow.DrawEditors (Boolean isRepaintEvent, UnityEditor.Editor[] editors, Boolean eyeDropperDirty) UnityEditor.InspectorWindow.OnGUI () System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/monoAndRuntimeClassLibs/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)