diff --git a/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/AsyncRunner.java b/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/AsyncRunner.java
index 859456cf3..776ee011a 100644
--- a/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/AsyncRunner.java
+++ b/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/AsyncRunner.java
@@ -24,7 +24,8 @@ public class AsyncRunner {
 
 	private static Scheduler executor = Schedulers.newSingle("STS4 Thread");
 
-	// Only need to remember the last request as requests are executed in order, if
+	// Used in test harness to wait for all pending request to finish.
+	// We only need to remember the last request as requests are executed in order, so if
 	// the last request is done, all requests are done
 	private CompletableFuture<?> lastRequest;
 
@@ -51,10 +52,15 @@ public class AsyncRunner {
 	}
 
 	public synchronized CompletableFuture<Void> execute(RunnableWithException runnable) {
-		CompletableFuture<Void> x = Mono.fromCallable(() -> {
-			runnable.run();
-			return (Void)null;
-		}).subscribeOn(executor).toFuture();
+		CompletableFuture<Void> x = Mono.<Void>fromRunnable(() -> {
+			try {
+				runnable.run();
+			} catch (Exception e) {
+				throw new RuntimeException(e);
+			}
+		})
+		.subscribeOn(executor)
+		.toFuture();
 		lastRequest = x;
 		return x;
 	}
diff --git a/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleLanguageServer.java b/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleLanguageServer.java
index 8cfd5c66f..1f4ee4e31 100644
--- a/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleLanguageServer.java
+++ b/headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/SimpleLanguageServer.java
@@ -188,12 +188,12 @@ public class SimpleLanguageServer implements Sts4LanguageServer, LanguageClientA
 					(String)params.getArguments().get(0), params.getArguments().get(1)
 			);
 			return quickfixResolve(quickfixParams)
-			.then((QuickfixEdit edit) -> {
+			.flatMap((QuickfixEdit edit) -> {
 				Mono<ApplyWorkspaceEditResponse> applyEdit = Mono.fromFuture(client.applyEdit(new ApplyWorkspaceEditParams(edit.workspaceEdit)));
 				Mono<Object> moveCursor = edit.cursorMovement==null
 						? Mono.just(new ApplyWorkspaceEditResponse(true))
 						: Mono.fromFuture(client.moveCursor(edit.cursorMovement));
-				return applyEdit.then(r -> r.getApplied() ? moveCursor : Mono.just(new ApplyWorkspaceEditResponse(true)));
+				return applyEdit.flatMap(r -> r.getApplied() ? moveCursor : Mono.just(new ApplyWorkspaceEditResponse(true)));
 			})
 			.toFuture();
 		}
@@ -568,7 +568,7 @@ public class SimpleLanguageServer implements Sts4LanguageServer, LanguageClientA
 //			}
 			engine.reconcile(doc, problems);
 		})
-		.otherwise(error -> {
+		.onErrorResume(error -> {
 			Log.log(error);
 			return Mono.empty();
 		})
diff --git a/headless-services/commons/pom.xml b/headless-services/commons/pom.xml
index e24ec1782..9ecba6fb3 100644
--- a/headless-services/commons/pom.xml
+++ b/headless-services/commons/pom.xml
@@ -81,7 +81,7 @@
 		<jersey-2-version>2.10</jersey-2-version>
 		<lsp4j-version>0.4.0-SNAPSHOT</lsp4j-version>
 		<!-- NOTE: Reactor version must match version used by the CF client -->
-		<reactor-version>3.0.5.RELEASE</reactor-version>
+		<reactor-version>3.1.5.RELEASE</reactor-version>
 		<reactor-netty>0.6.0.RELEASE</reactor-netty>
 		<cloudfoundry-client-version>2.4.0.RELEASE</cloudfoundry-client-version>
 		<commons-io-version>2.4</commons-io-version>