diff --git a/FileHandlers/FileRead.cs b/FileHandlers/FileRead.cs
index a9bc0a2..d5e2b15 100644
--- a/FileHandlers/FileRead.cs
+++ b/FileHandlers/FileRead.cs
@@ -165,7 +165,7 @@ public partial class FileRead : FileReaderHandler, ISMTP
                 Equipment.SelfDescriptionBuilder.AddParameterTypeDefinition(structuredType);
             }
             if (!parameterTypeDefinitions.ContainsKey(jsonProperty.Value.ValueKind))
-                throw new Exception(string.Concat('{', jsonProperty.Value.ValueKind, "} is not mapped!"));
+                throw new Exception(string.Concat('<', jsonProperty.Name, "> {", jsonProperty.Value.ValueKind, "} is not mapped!"));
         }
         foreach (JsonProperty jsonProperty in jsonProperties)
         {