diff --git a/amber/src/main/scala/org/apache/texera/amber/engine/common/rpc/AsyncRPCServer.scala b/amber/src/main/scala/org/apache/texera/amber/engine/common/rpc/AsyncRPCServer.scala
index e9a3e2cc455..b6a5e2594c1 100644
--- a/amber/src/main/scala/org/apache/texera/amber/engine/common/rpc/AsyncRPCServer.scala
+++ b/amber/src/main/scala/org/apache/texera/amber/engine/common/rpc/AsyncRPCServer.scala
@@ -103,9 +103,9 @@ class AsyncRPCServer(
         // if error occurs, return it to the sender.
         logger.error("Exception occurred", err)
         returnResult(senderID, id, mkControlError(err))
-      // if throw this exception right now, the above message might not be able
-      // to be sent out. We do not throw for now.
-      //        throw err
+        // Re-throw Errors (e.g. failed assertions) after replying; only
+        // Exceptions are returned to the sender and recovered from.
+        if (err.isInstanceOf[Error]) throw err
     }
   }
 
diff --git a/amber/src/test/scala/org/apache/texera/amber/engine/architecture/worker/WorkerSpec.scala b/amber/src/test/scala/org/apache/texera/amber/engine/architecture/worker/WorkerSpec.scala
index df9cb086a60..25686ade433 100644
--- a/amber/src/test/scala/org/apache/texera/amber/engine/architecture/worker/WorkerSpec.scala
+++ b/amber/src/test/scala/org/apache/texera/amber/engine/architecture/worker/WorkerSpec.scala
@@ -173,7 +173,7 @@ class WorkerSpec
     )
     val addPort1 = AsyncRPCClient.ControlInvocation(
       METHOD_ASSIGN_PORT,
-      AssignPortRequest(mockPortId, input = true, mkSchema(1).toRawSchema, List(""), List()),
+      AssignPortRequest(mockPortId, input = true, mkSchema(1).toRawSchema, List(), List()),
       AsyncRPCContext(CONTROLLER, identifier1),
       1
     )