diff --git a/lualib/skynet.lua b/lualib/skynet.lua
index 3f260b3e..522a0a9a 100644
--- a/lualib/skynet.lua
+++ b/lualib/skynet.lua
@@ -309,7 +309,10 @@ function skynet.call(addr, typename, ...)
 	if watching_service[addr] == false then
 		error("Service is dead")
 	end
-	local session = assert(c.send(addr, p.id , nil , p.pack(...)),"call to invalid address")
+	local session = c.send(addr, p.id , nil , p.pack(...))
+	if session == nil then
+		error("call to invalid address " .. tostring(addr))
+	end
 	return p.unpack(yield_call(addr, session))
 end
 
@@ -319,7 +322,7 @@ function skynet.blockcall(addr, typename , ...)
 	local session = c.send(addr, p.id , nil , p.pack(...))
 	if session == nil then
 		c.command("UNLOCK")
-		error("call to invalid address")
+		error("call to invalid address " .. tostring(addr))
 	end
 	return p.unpack(yield_call(addr, session))
 end
diff --git a/service-src/service_client.c b/service-src/service_client.c
index 1bc5c788..e31f9705 100644
--- a/service-src/service_client.c
+++ b/service-src/service_client.c
@@ -41,6 +41,8 @@ _cb(struct skynet_context * context, void * ud, int type, int session, uint32_t
 int
 client_init(struct client *c, struct skynet_context *ctx, const char * args) {
 	int id = 0;
+	if (args == NULL)
+		return 1;
 	sscanf(args, "%d",&id);
 	c->id = id;
 	skynet_callback(ctx, c, _cb);
diff --git a/service-src/service_gate.c b/service-src/service_gate.c
index 78d6c142..a97dfdcf 100644
--- a/service-src/service_gate.c
+++ b/service-src/service_gate.c
@@ -330,6 +330,8 @@ start_listen(struct gate *g, char * listen_addr) {
 
 int
 gate_init(struct gate *g , struct skynet_context * ctx, char * parm) {
+	if (parm == NULL)
+		return 1;
 	int max = 0;
 	int buffer = 0;
 	int sz = strlen(parm)+1;
diff --git a/skynet-src/skynet_harbor.c b/skynet-src/skynet_harbor.c
index f188e252..023f1f6d 100644
--- a/skynet-src/skynet_harbor.c
+++ b/skynet-src/skynet_harbor.c
@@ -34,7 +34,8 @@ skynet_harbor_register(struct remote_name *rname) {
 
 int 
 skynet_harbor_message_isremote(uint32_t handle) {
-	return (handle & ~HANDLE_MASK) != HARBOR;
+	int h = (handle & ~HANDLE_MASK);
+	return h != HARBOR && h !=0;
 }
 
 void
diff --git a/skynet-src/skynet_server.c b/skynet-src/skynet_server.c
index b6da1834..9b80b093 100644
--- a/skynet-src/skynet_server.c
+++ b/skynet-src/skynet_server.c
@@ -120,10 +120,11 @@ skynet_context_new(const char * name, const char *param) {
 		}
 		skynet_mq_force_push(queue);
 		if (ret) {
-			printf("[:%x] launch %s %s\n",ret->handle, name, param ? param : "");
+			skynet_error(ret, "LAUNCH %s %s", name, param ? param : "");
 		}
 		return ret;
 	} else {
+		skynet_error(ctx, "FAILED launch %s", name);
 		skynet_context_release(ctx);
 		skynet_handle_retire(ctx->handle);
 		skynet_mq_release(queue);
@@ -358,9 +359,11 @@ static void
 handle_exit(struct skynet_context * context, uint32_t handle) {
 	if (handle == 0) {
 		handle = context->handle;
+		skynet_error(context, "KILL self");
 	}
 	if (G_NODE.monitor_exit) {
 		skynet_send(context,  handle, G_NODE.monitor_exit, PTYPE_CLIENT, 0, NULL, 0);
+		skynet_error(context, "KILL :%0x", handle);
 	}
 	skynet_handle_retire(handle);
 }
@@ -476,7 +479,6 @@ skynet_command(struct skynet_context * context, const char * cmd , const char *
 		args = strsep(&args, "\r\n");
 		struct skynet_context * inst = skynet_context_new(mod,args);
 		if (inst == NULL) {
-			fprintf(stderr, "Launch %s %s failed\n",mod,args);
 			return NULL;
 		} else {
 			_id_to_hex(context->result, inst->handle);