diff --git a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/FnApiWindowMappingFn.java b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/FnApiWindowMappingFn.java
index 7e298e7..dcf15f4 100644
--- a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/FnApiWindowMappingFn.java
+++ b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/FnApiWindowMappingFn.java
@@ -56,7 +56,6 @@
 import org.apache.beam.sdk.util.WindowedValue;
 import org.apache.beam.sdk.values.KV;
 import org.apache.beam.sdk.values.WindowingStrategy;
-import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Strings;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.Cache;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.CacheBuilder;
 import org.slf4j.Logger;
@@ -253,7 +252,7 @@
       }
 
       // Check to see if processing the request failed.
-      throwIfFailure(processResponse);
+      MoreFutures.get(processResponse);
 
       waitForInboundTermination.awaitCompletion();
       WindowedValue<KV<byte[], TargetWindowT>> sideInputWindow = outputValue.poll();
@@ -300,22 +299,10 @@
                               processBundleDescriptor.toBuilder().setId(descriptorId).build())
                           .build())
                   .build());
-      throwIfFailure(response);
+      // Check if the bundle descriptor is registered successfully.
+      MoreFutures.get(response);
       processBundleDescriptorId = descriptorId;
     }
     return processBundleDescriptorId;
   }
-
-  private static InstructionResponse throwIfFailure(
-      CompletionStage<InstructionResponse> responseFuture)
-      throws ExecutionException, InterruptedException {
-    InstructionResponse response = MoreFutures.get(responseFuture);
-    if (!Strings.isNullOrEmpty(response.getError())) {
-      throw new IllegalStateException(
-          String.format(
-              "Client failed to process %s with error [%s].",
-              response.getInstructionId(), response.getError()));
-    }
-    return response;
-  }
 }
diff --git a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/fn/control/RegisterAndProcessBundleOperation.java b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/fn/control/RegisterAndProcessBundleOperation.java
index 0a3346c..bf42c4d 100644
--- a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/fn/control/RegisterAndProcessBundleOperation.java
+++ b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/fn/control/RegisterAndProcessBundleOperation.java
@@ -370,12 +370,8 @@
    * elements consumed from the upstream read operation.
    *
    * <p>May be called at any time, including before start() and after finish().
-   *
-   * @throws InterruptedException
-   * @throws ExecutionException
    */
-  public CompletionStage<BeamFnApi.ProcessBundleProgressResponse> getProcessBundleProgress()
-      throws InterruptedException, ExecutionException {
+  public CompletionStage<BeamFnApi.ProcessBundleProgressResponse> getProcessBundleProgress() {
     // processBundleId may be reset if this bundle finishes asynchronously.
     String processBundleId = this.processBundleId;
 
@@ -393,13 +389,7 @@
 
     return instructionRequestHandler
         .handle(processBundleRequest)
-        .thenApply(
-            response -> {
-              if (!response.getError().isEmpty()) {
-                throw new IllegalStateException(response.getError());
-              }
-              return response.getProcessBundleProgress();
-            });
+        .thenApply(InstructionResponse::getProcessBundleProgress);
   }
 
   /** Returns the final metrics returned by the SDK harness when it completes the bundle. */
@@ -636,53 +626,36 @@
     return true;
   }
 
-  private static CompletionStage<BeamFnApi.InstructionResponse> throwIfFailure(
+  private static CompletionStage<BeamFnApi.ProcessBundleResponse> getProcessBundleResponse(
       CompletionStage<InstructionResponse> responseFuture) {
     return responseFuture.thenApply(
         response -> {
-          if (!response.getError().isEmpty()) {
-            throw new IllegalStateException(
-                String.format(
-                    "Client failed to process %s with error [%s].",
-                    response.getInstructionId(), response.getError()));
+          switch (response.getResponseCase()) {
+            case PROCESS_BUNDLE:
+              return response.getProcessBundle();
+            default:
+              throw new IllegalStateException(
+                  String.format(
+                      "SDK harness returned wrong kind of response to ProcessBundleRequest: %s",
+                      TextFormat.printToString(response)));
           }
-          return response;
         });
   }
 
-  private static CompletionStage<BeamFnApi.ProcessBundleResponse> getProcessBundleResponse(
-      CompletionStage<InstructionResponse> responseFuture) {
-    return throwIfFailure(responseFuture)
-        .thenApply(
-            response -> {
-              switch (response.getResponseCase()) {
-                case PROCESS_BUNDLE:
-                  return response.getProcessBundle();
-                default:
-                  throw new IllegalStateException(
-                      String.format(
-                          "SDK harness returned wrong kind of response to ProcessBundleRequest: %s",
-                          TextFormat.printToString(response)));
-              }
-            });
-  }
-
   private static CompletionStage<BeamFnApi.RegisterResponse> getRegisterResponse(
-      CompletionStage<InstructionResponse> responseFuture)
-      throws ExecutionException, InterruptedException {
-    return throwIfFailure(responseFuture)
-        .thenApply(
-            response -> {
-              switch (response.getResponseCase()) {
-                case REGISTER:
-                  return response.getRegister();
-                default:
-                  throw new IllegalStateException(
-                      String.format(
-                          "SDK harness returned wrong kind of response to RegisterRequest: %s",
-                          TextFormat.printToString(response)));
-              }
-            });
+      CompletionStage<InstructionResponse> responseFuture) {
+    return responseFuture.thenApply(
+        response -> {
+          switch (response.getResponseCase()) {
+            case REGISTER:
+              return response.getRegister();
+            default:
+              throw new IllegalStateException(
+                  String.format(
+                      "SDK harness returned wrong kind of response to RegisterRequest: %s",
+                      TextFormat.printToString(response)));
+          }
+        });
   }
 
   private static void cancelIfNotNull(CompletionStage<?> future) {
diff --git a/runners/java-fn-execution/src/main/java/org/apache/beam/runners/fnexecution/control/InstructionRequestHandler.java b/runners/java-fn-execution/src/main/java/org/apache/beam/runners/fnexecution/control/InstructionRequestHandler.java
index b655732..8a9dc75 100644
--- a/runners/java-fn-execution/src/main/java/org/apache/beam/runners/fnexecution/control/InstructionRequestHandler.java
+++ b/runners/java-fn-execution/src/main/java/org/apache/beam/runners/fnexecution/control/InstructionRequestHandler.java
@@ -20,7 +20,10 @@
 import java.util.concurrent.CompletionStage;
 import org.apache.beam.model.fnexecution.v1.BeamFnApi;
 
-/** Interface for any function that can handle a Fn API {@link BeamFnApi.InstructionRequest}. */
+/**
+ * Interface for any function that can handle a Fn API {@link BeamFnApi.InstructionRequest}. Any
+ * error responses will be converted to exceptionally completed futures.
+ */
 public interface InstructionRequestHandler extends AutoCloseable {
   CompletionStage<BeamFnApi.InstructionResponse> handle(BeamFnApi.InstructionRequest request);
 }