diff --git a/libcore/core.go b/libcore/core.go
index 2f6db83b..6d78afac 100644
--- a/libcore/core.go
+++ b/libcore/core.go
@@ -16,15 +16,11 @@ func Unsetenv(key string) error {
 	return os.Unsetenv(key)
 }
 
-func initCoreDefer() {
-	device.AllDefer("InitCore", ForceLog)
-}
-
 func InitCore(internalAssets string, externalAssets string, prefix string, useOfficial BoolFunc, // extractV2RayAssets
 	cachePath string, process string, //InitCore
 	enableLog bool, maxKB int32, //SetEnableLog
 ) {
-	defer initCoreDefer()
+	defer device.DeferPanicToError("InitCore", func(err error) { ForceLog(fmt.Sprintln(err)) })
 
 	isBgProcess := strings.HasSuffix(process, ":bg")
 
@@ -41,12 +37,12 @@ func InitCore(internalAssets string, externalAssets string, prefix string, useOf
 		go ForceLog(s)
 	} else {
 		// not fatal
-		ForceLog(fmt.Sprintln("Log not inited:", s, err.Error()))
+		// ForceLog(fmt.Sprintln("Log not inited:", s, err.Error()))
 	}
 
 	// Set up some component
 	go func() {
-		defer initCoreDefer()
+		defer device.DeferPanicToError("InitCore-go", func(err error) { ForceLog(fmt.Sprintln(err)) })
 		device.GoDebug(process)
 
 		externalAssetsPath = externalAssets
diff --git a/libcore/device/debug.go b/libcore/device/debug.go
index 889442c3..016c17fe 100644
--- a/libcore/device/debug.go
+++ b/libcore/device/debug.go
@@ -13,9 +13,9 @@ func GoDebug(any interface{}) {
 	}
 }
 
-func AllDefer(name string, log func(string)) {
+func DeferPanicToError(name string, err func(error)) {
 	if r := recover(); r != nil {
-		s := fmt.Sprintln(name+" panic", r, string(debug.Stack()))
-		log(s)
+		s := fmt.Errorf("%s panic: %s\n%s", name, r, string(debug.Stack()))
+		err(s)
 	}
 }
diff --git a/libcore/speedtest.go b/libcore/speedtest.go
index 4bbb38f2..7f9c1c28 100644
--- a/libcore/speedtest.go
+++ b/libcore/speedtest.go
@@ -3,6 +3,8 @@ package libcore
 import (
 	"context"
 	"fmt"
+	"libcore/device"
+	"log"
 	"math/rand"
 	"net/http"
 	"strings"
@@ -13,6 +15,8 @@ import (
 )
 
 func UrlTestV2ray(instance *V2RayInstance, inbound string, link string, timeout int32) (int32, error) {
+	defer device.DeferPanicToError("UrlTestV2ray", func(err error) { log.Println(err) })
+
 	transport := &http.Transport{
 		TLSHandshakeTimeout: time.Duration(timeout) * time.Millisecond,
 		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
diff --git a/libcore/v2ray.go b/libcore/v2ray.go
index 498099a5..2b54ad0c 100644
--- a/libcore/v2ray.go
+++ b/libcore/v2ray.go
@@ -3,6 +3,7 @@ package libcore
 import (
 	"context"
 	"fmt"
+	"libcore/device"
 	"log"
 	"strings"
 	"sync"
@@ -39,6 +40,8 @@ func NewV2rayInstance() *V2RayInstance {
 }
 
 func (instance *V2RayInstance) LoadConfig(content string) error {
+	defer device.DeferPanicToError("LoadConfig", func(err error) { log.Println(err) })
+
 	instance.access.Lock()
 	defer instance.access.Unlock()
 
@@ -77,6 +80,8 @@ func (instance *V2RayInstance) LoadConfig(content string) error {
 }
 
 func (instance *V2RayInstance) Start() error {
+	defer device.DeferPanicToError("Start", func(err error) { log.Println(err) })
+
 	instance.access.Lock()
 	defer instance.access.Unlock()
 	if instance.started {
@@ -105,6 +110,8 @@ func (instance *V2RayInstance) QueryStats(tag string, direct string) int64 {
 }
 
 func (instance *V2RayInstance) Close() error {
+	defer device.DeferPanicToError("Close", func(err error) { log.Println(err) })
+
 	instance.access.Lock()
 	defer instance.access.Unlock()
 	if instance.started {