diff --git a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
index 52978bb..c03d02f 100644
--- a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
+++ b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
@@ -59,13 +59,7 @@ public abstract class Oms
 		MethodImplementation[] methodImplementations = MBS.Core.Reflection.TypeLoader.GetAvailableTypes<MethodImplementation>(new System.Reflection.Assembly[] { Assembly.GetExecutingAssembly() });
 		foreach (MethodImplementation impl in methodImplementations)
 		{
-			if (TryGetInstance(impl.MethodClassGuid, out InstanceHandle methodClassInstance))
-			{
-				RegisterMethodImplementation(methodClassInstance, impl);
-			}
-			else{
-				Console.WriteLine("failed to load method type '{0}' from instance {1} (inst not found)", impl.GetType().FullName, impl.MethodClassGuid);
-			}
+			RegisterMethodImplementation(impl.MethodClassGuid, impl);
 		}
 	}
 
@@ -669,10 +663,10 @@ public abstract class Oms
 		return value;
 	}
 
-	private Dictionary<InstanceHandle, MethodImplementation> methodImplementations = new Dictionary<InstanceHandle, MethodImplementation>();
-	private void RegisterMethodImplementation(InstanceHandle methodClass, MethodImplementation implementation)
+	private Dictionary<Guid, MethodImplementation> methodImplementations = new Dictionary<Guid, MethodImplementation>();
+	private void RegisterMethodImplementation(Guid methodClassId, MethodImplementation implementation)
 	{
-		methodImplementations[methodClass] = implementation;
+		methodImplementations[methodClassId] = implementation;
 		implementation.Initialize(this);
 	}
 
@@ -705,6 +699,8 @@ public abstract class Oms
 	public InstanceHandle Execute(OmsContext context, InstanceHandle methodOrMethodBinding, InstanceHandle? targetInstance = null)
 	{
 		InstanceHandle parentClass = GetParentClass(methodOrMethodBinding);
+		Guid parentClassId = GetGlobalIdentifier(parentClass);
+
 		if (IsInstanceOf(methodOrMethodBinding, GetInstance(KnownInstanceGuids.Classes.MethodBinding)))
 		/*
 		if (IsInstanceOf(methodOrMethodBinding, GetInstance(KnownInstanceGuids.Classes.ReturnAttributeMethodBinding))
@@ -728,7 +724,7 @@ public abstract class Oms
 		}
 		else
 		{
-			if (methodImplementations.ContainsKey(parentClass))
+			if (methodImplementations.ContainsKey(parentClassId))
 			{
 				if (targetInstance != null)
 				{
@@ -736,7 +732,7 @@ public abstract class Oms
 					InstanceHandle pclassInstance = GetParentClass(hh);
 					context.SetWorkData(pclassInstance, hh);
 				}
-				return methodImplementations[parentClass].Execute(this, context, methodOrMethodBinding);
+				return methodImplementations[parentClassId].Execute(this, context, methodOrMethodBinding);
 			}
 		}
 		throw new NotImplementedException(String.Format("method implementation not found for method class {0}", GetGlobalIdentifier(parentClass)));
@@ -837,17 +833,7 @@ public abstract class Oms
 	private string _GetInstanceTextHack(InstanceHandle inst)
 	{
 		StringBuilder sb = new StringBuilder();
-		if (IsInstanceOf(inst, GetInstance(KnownInstanceGuids.Classes.Class)))
-		{
-			string name = GetAttributeValue<string>(inst, GetInstance(KnownAttributeGuids.Text.Name));
-			sb.Append(name);
-		}
-		else if (IsInstanceOf(inst, GetInstance(KnownInstanceGuids.Classes.Attribute)))
-		{
-			string name = GetAttributeValue<string>(inst, GetInstance(KnownAttributeGuids.Text.Name));
-			sb.Append(name);
-		}
-		else if (IsInstanceOf(inst, GetInstance(KnownInstanceGuids.Classes.Relationship)))
+		if (IsInstanceOf(inst, GetInstance(KnownInstanceGuids.Classes.Relationship)))
 		{
 			InstanceHandle sourceClass = GetRelatedInstance(inst, GetInstance(KnownRelationshipGuids.Relationship__has_source__Class));
 			string relationshipType = GetAttributeValue<string>(inst, GetInstance(KnownAttributeGuids.Text.RelationshipType));
@@ -892,6 +878,14 @@ public abstract class Oms
 			sb.Append(GetInstanceText(executesMethod));
 			sb.Append("[rsmb]");
 		}
+		else
+		{
+			string name = GetAttributeValue<string>(inst, GetInstance(KnownAttributeGuids.Text.Name));
+			if (name != null)
+			{
+				sb.Append(name);
+			}
+		}
 		return sb.ToString();
 	}