diff --git a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
index 1257cbe0..46a15cf0 100644
--- a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
+++ b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
@@ -337,7 +337,7 @@ class Shadowsocks
         if (intent != null) {
           startActivityForResult(intent, Shadowsocks.REQUEST_CONNECT)
         } else {
-          onActivityResult(Shadowsocks.REQUEST_CONNECT, Activity.RESULT_OK, null)
+          handler.post(() => onActivityResult(Shadowsocks.REQUEST_CONNECT, Activity.RESULT_OK, null))
         }
       } else {
         serviceStart()
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
index 34b76279..28c43504 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
@@ -442,11 +442,14 @@ class ShadowsocksVpnService extends VpnService with BaseService {
 
     try {
       conn = builder.establish()
+      if (conn == null) throw new Exception("Application not prepared.")
     } catch {
       case ex: IllegalStateException =>
         changeState(State.STOPPED, ex.getMessage)
         conn = null
-      case ex: Exception => conn = null
+      case ex: Exception =>
+        ex.printStackTrace()
+        conn = null
     }
 
     if (conn == null) {