diff --git a/config.go b/config.go
index a680c4a..ebeb6f7 100644
--- a/config.go
+++ b/config.go
@@ -48,7 +48,10 @@ func (c *Config) add(app AppConfig) {
 
 func (c *Config) save() {
 	data, _ := json.MarshalIndent(c, "", "")
-	ioutil.WriteFile("config.json", data, 0644)
+	err := ioutil.WriteFile("config.json", data, 0644)
+	if err != nil {
+		gLog.Println(LevelERROR, "save config.json error:", err)
+	}
 }
 
 func (c *Config) load() error {
diff --git a/daemon.go b/daemon.go
index 16f5339..8352730 100644
--- a/daemon.go
+++ b/daemon.go
@@ -148,11 +148,15 @@ func install() {
 	config.SrcPort = *srcPort
 	config.Protocol = *protocol
 	gConf.add(config)
-	os.Chdir(defaultInstallPath)
+	os.MkdirAll(defaultInstallPath, 0775)
+	err := os.Chdir(defaultInstallPath)
+	if err != nil {
+		gLog.Println(LevelERROR, "cd error:", err)
+	}
 	gConf.save()
 
 	// copy files
-	os.MkdirAll(defaultInstallPath, 0775)
+
 	targetPath := filepath.Join(defaultInstallPath, defaultBinName)
 	binPath, _ := os.Executable()
 	src, errFiles := os.Open(binPath) // can not use args[0], on Windows call openp2p is ok(=openp2p.exe)
@@ -180,7 +184,7 @@ func install() {
 
 	// args := []string{""}
 	gLog.Println(LevelINFO, "targetPath:", targetPath)
-	err := d.Control("install", targetPath, []string{"-d", "-f"})
+	err = d.Control("install", targetPath, []string{"-d", "-f"})
 	if err != nil {
 		gLog.Println(LevelERROR, "install system service error:", err)
 	} else {
diff --git a/errorcode.go b/errorcode.go
new file mode 100644
index 0000000..f588882
--- /dev/null
+++ b/errorcode.go
@@ -0,0 +1,13 @@
+package main
+
+import (
+	"errors"
+)
+
+// error message
+var (
+	// ErrorS2S string = "s2s is not supported"
+	// ErrorHandshake string = "handshake error"
+	ErrorS2S       = errors.New("s2s is not supported")
+	ErrorHandshake = errors.New("handshake error")
+)
diff --git a/protocol.go b/protocol.go
index de4575b..ac18471 100644
--- a/protocol.go
+++ b/protocol.go
@@ -4,14 +4,13 @@ import (
 	"bytes"
 	"encoding/binary"
 	"encoding/json"
-	"errors"
 	"hash/crc64"
 	"math/big"
 	"net"
 	"time"
 )
 
-const OpenP2PVersion = "0.97.0"
+const OpenP2PVersion = "0.97.1"
 const ProducnName string = "openp2p"
 
 type openP2PHeader struct {
@@ -131,14 +130,6 @@ const (
 	NatTestTimeout               = time.Second * 10
 )
 
-// error message
-var (
-	// ErrorS2S string = "s2s is not supported"
-	// ErrorHandshake string = "handshake error"
-	ErrorS2S       = errors.New("s2s is not supported")
-	ErrorHandshake = errors.New("handshake error")
-)
-
 // NATNone has public ip
 const (
 	NATNone      = 0