diff --git a/mocha-common b/mocha-common
index be11f42..12ac9ab 160000
--- a/mocha-common
+++ b/mocha-common
@@ -1 +1 @@
-Subproject commit be11f42a37a0845286dc522c47d802ac2977a7ee
+Subproject commit 12ac9ab8c068f850ec7a3850e95562accbe91725
diff --git a/mocha-dotnet/src/lib/Mocha.Core/KnownInstanceGuids.cs b/mocha-dotnet/src/lib/Mocha.Core/KnownInstanceGuids.cs
index b4111d1..09b38b9 100755
--- a/mocha-dotnet/src/lib/Mocha.Core/KnownInstanceGuids.cs
+++ b/mocha-dotnet/src/lib/Mocha.Core/KnownInstanceGuids.cs
@@ -204,7 +204,8 @@ namespace Mocha.Core
             }
 			public static class ConditionalSelectAttribute
 			{
-				public static Guid Method__get__Method_Abbreviation { get; } = new Guid("{f0c64709-385d-481b-8f58-83e507fb261c}");
+				// public static Guid Method__get__Method_Abbreviation { get; } = new Guid("{f0c64709-385d-481b-8f58-83e507fb261c}");
+				public static Guid Method__get__Method_Abbreviation { get; } = new Guid("{ddb62bd1-df5a-4c9d-9991-ff9a827717e9}");
 				public static Guid Method_Binding__get__Method_Binding_Abbreviation { get; } = new Guid("{7154cb08-0f80-4af4-bca5-c2c12e54479a}");
 			}
 			public static class GetAttributeBySystemRoutine
diff --git a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
index 6291dd1..f7e6798 100644
--- a/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
+++ b/mocha-dotnet/src/lib/Mocha.Core/Oms.cs
@@ -258,7 +258,7 @@ public abstract class Oms
 		{
 			return ih;
 		}
-		throw new KeyNotFoundException();
+		throw new KeyNotFoundException("inst not found: " + globalIdentifier.ToString("b"));
 	}
 
 	protected abstract IReadOnlyCollection<InstanceHandle> GetRelatedInstancesInternal(InstanceHandle source, InstanceHandle relationship, DateTime effectiveDate);
diff --git a/mocha-dotnet/tests/Mocha.Core.Tests/MethodTests/ConditionalSelectAttributeMethodTests.cs b/mocha-dotnet/tests/Mocha.Core.Tests/MethodTests/ConditionalSelectAttributeMethodTests.cs
index 8f1b2ac..53d7cc1 100644
--- a/mocha-dotnet/tests/Mocha.Core.Tests/MethodTests/ConditionalSelectAttributeMethodTests.cs
+++ b/mocha-dotnet/tests/Mocha.Core.Tests/MethodTests/ConditionalSelectAttributeMethodTests.cs
@@ -22,6 +22,39 @@ namespace Mocha.Core.Tests.MethodTests;
 
 public class ConditionalSelectAttributeMethodTests : MethodTestsBase
 {
+	public static IEnumerable<TestCaseData> Get_Method_Abbreviation__Cases
+	{
+		get
+		{
+			yield return new TestCaseData(KnownInstanceGuids.MethodClasses.AssignAttributeMethod).Returns("AA");
+			yield return new TestCaseData(KnownInstanceGuids.MethodClasses.GetRelationshipMethod).Returns("GR");
+		}
+	}
+
+	[TestCaseSource(nameof(Get_Method_Abbreviation__Cases))]
+	public string Get_Method_Abbreviation(Guid instanceGuid)
+	{
+		InstanceHandle c_Method = Oms.GetInstance(KnownInstanceGuids.Classes.Method);
+		
+		ConditionalSelectAttributeMethod sac = Oms.GetInstance<ConditionalSelectAttributeMethod>(KnownInstanceGuids.Methods.ConditionalSelectAttribute.Method__get__Method_Abbreviation);
+		ReturnAttributeMethodBinding ramb = sac.CreateMethodBinding(Oms);
+
+		OmsContext context = Oms.CreateContext();
+		context.SetWorkData(c_Method, sac);
+
+		InstanceHandle wd = Oms.Execute(context, ramb);
+		object? value = context.GetWorkData(wd);
+		if (value is string)
+		{
+			return (string)value;
+		}
+		return String.Empty;
+	}
+
+
+
+
+
 	[Test]
 	public void Test__Get_Method_Abbreviation__SAC()
 	{