Change return type of Clone method in derived class.

ICSharpCode.Decompiler/DecompilerSettings.cs

@@ -2238,7 +2238,7 @@ namespace ICSharpCode.Decompiler
 			}
 		}
 
-		public DecompilerSettings Clone()
+		public virtual DecompilerSettings Clone()
 		{
 			DecompilerSettings settings = (DecompilerSettings)MemberwiseClone();
 			if (csharpFormattingOptions != null)

ILSpy/Options/DecompilerSettings.cs

@@ -17,8 +17,6 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System.ComponentModel;
-
-using ICSharpCode.ILSpyX.Settings;
 using System.Linq;
 using System.Reflection;
 using System.Xml.Linq;
@@ -56,5 +54,10 @@ namespace ICSharpCode.ILSpy.Options
 					p.SetValue(this, value.Value);
 			}
 		}
+
+		public override DecompilerSettings Clone()
+		{
+			return (DecompilerSettings)base.Clone();
+		}
 	}
 }