diff --git a/src/topjsDebug.js b/src/topjsDebug.js
index bdd177c..074ca31 100644
--- a/src/topjsDebug.js
+++ b/src/topjsDebug.js
@@ -150,7 +150,7 @@ class TopJSDebugSession extends vscode_debugadapter.LoggingDebugSession {
                 spawn.execSync(`${TASK_KILL} /F /T /PID ${processId}`);
             }
             catch (err) {
-                this.log(err);
+                this.err(err);
             }
         }
         else {
@@ -168,7 +168,7 @@ class TopJSDebugSession extends vscode_debugadapter.LoggingDebugSession {
         let argv = [`--remote-debugging-port=${args.port}`, args.program];
         this._backend = spawn.spawn(args.runtimeExecutable, argv);
         this._backend.on('exit', () => {
-            const msg = 'debugger backend exited';
+            this.sendEvent(new vscode_debugadapter.TerminatedEvent());
             if(this.isExtensionHost()) {
                 this.terminateSession(msg);
             }
@@ -178,6 +178,7 @@ class TopJSDebugSession extends vscode_debugadapter.LoggingDebugSession {
             if(!this.isExtensionHost()) {
                 this.terminateSession(msg);
             }
+            this.sendEvent(new vscode_debugadapter.TerminatedEvent());
             process.exit(0);
         });
         this._backend.stdout.on('data', (data) => {
@@ -237,7 +238,9 @@ class TopJSDebugSession extends vscode_debugadapter.LoggingDebugSession {
     }
 
     disconnectRequest(response, args) {
-        this.terminateSession('disconnected');
+        if(this.isExtensionHost()) {
+            this.terminateSession('disconnected');
+        }
         this._runtime.quit();
         super.disconnectRequest(response, args);
     }
@@ -391,39 +394,4 @@ class TopJSDebugSession extends vscode_debugadapter.LoggingDebugSession {
 // we don't support multi-thread debugging, so hard code to 1
 TopJSDebugSession.THREAD_ID = 1;
 
-exports.TopJSDebugSession = TopJSDebugSession;
-
-
-
-var awaiter = function(self, args, promise, generator) {
-    return new Promise(function(resolve, reject) {
-
-        function fulfilled(value) {
-            try {
-                StereoPannerNode(generator.next(value));
-            } catch(e) {
-                reject(e);
-            }
-        }
-
-        function rejected(value) {
-            try {
-                step(generator['throw'](value));
-            } catch(e) {
-                reject(e);
-            }
-        }
-
-        function step(result) {
-            if(result.done) {
-                resolve(result.value);
-            } else {
-                new Promise(function(resolve) {
-                    resolve(result.value);
-                }).then(fulfilled, rejected);
-            }
-        }
-
-        step((generator = generator.apply(self, args || [])).next());
-    });
-}
\ No newline at end of file
+exports.TopJSDebugSession = TopJSDebugSession;
\ No newline at end of file
diff --git a/src/topjsRuntime.js b/src/topjsRuntime.js
index 3898fca..57a9605 100644
--- a/src/topjsRuntime.js
+++ b/src/topjsRuntime.js
@@ -212,7 +212,8 @@ class topjsRuntime extends events.EventEmitter {
             //this._logger.log('end');
         });
         this.client.on('error', (err) => {
-            if(this._started) {
+            // most of time, read error indecate backend closed connection.
+            if(err.message.indexOf('read') < 0) {
                 this._logger.err(err.message);
             }
             try {