Fix #437

src/main/res/values-zh/strings.xml

@@ -40,6 +40,7 @@
   <string name="stop">停止服务</string>
   <string name="stopping">正在关闭……</string>
   <string name="vpn_error">后台服务启动失败：%s</string>
+  <string name="reboot_required">VPN 服务启动失败。你可能需要重启设备。</string>
   <string name="close">关闭</string>
   <string name="proxy_empty">代理服务器地址不能为空</string>
   <string name="connect">连接</string>

src/main/res/values/strings.xml

@@ -66,6 +66,7 @@
   <string name="stop">Stop the service</string>
   <string name="stopping">Shutting down…</string>
   <string name="vpn_error">%s</string>
+  <string name="reboot_required">Failed to start VPN service. You might need to reboot your device.</string>
 
   <!-- alert category -->
   <string name="close">Close</string>

src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala

@@ -442,7 +442,7 @@ class ShadowsocksVpnService extends VpnService with BaseService {
 
     try {
       conn = builder.establish()
-      if (conn == null) throw new Exception("Application not prepared.")
+      if (conn == null) changeState(State.STOPPED, getString(R.string.reboot_required))
     } catch {
       case ex: IllegalStateException =>
         changeState(State.STOPPED, ex.getMessage)