diff --git a/presto-main/src/main/java/io/prestosql/sql/gen/RowExpressionCompiler.java b/presto-main/src/main/java/io/prestosql/sql/gen/RowExpressionCompiler.java
index 4558e2087..0a6c2c1df 100644
--- a/presto-main/src/main/java/io/prestosql/sql/gen/RowExpressionCompiler.java
+++ b/presto-main/src/main/java/io/prestosql/sql/gen/RowExpressionCompiler.java
@@ -113,7 +113,7 @@ public class RowExpressionCompiler
                             functionAndTypeManager);
                     return (new FunctionCallCodeGenerator()).generateExpression(call.getFunctionHandle(), generatorContext, call.getType(), call.getArguments());
                 default:
-                    throw new IllegalArgumentException(format("Unsupported function implementation type in RowExpressionCompiler: %s", functionMetadata.getImplementationType()));
+                    throw new IllegalArgumentException(format("Unsupported function implementation type in RowExpressionCompiler: %s. For the external function, we will support to execute them in the future release.", functionMetadata.getImplementationType()));
             }
         }
 
diff --git a/presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java b/presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java
index 5882ca673..1231aff99 100644
--- a/presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java
+++ b/presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java
@@ -1604,7 +1604,7 @@ public class LocalExecutionPlanner
                 }
             }
             catch (RuntimeException e) {
-                throw new PrestoException(COMPILER_ERROR, "Compiler failed", e);
+                throw new PrestoException(COMPILER_ERROR, "Execution Compiler failed.", e);
             }
         }