diff --git a/common/buf/multi_buffer.go b/common/buf/multi_buffer.go
index dd8961501..95149b4a2 100644
--- a/common/buf/multi_buffer.go
+++ b/common/buf/multi_buffer.go
@@ -3,6 +3,7 @@ package buf
 import (
 	"io"
 	"net"
+	"os"
 
 	"v2ray.com/core/common"
 	"v2ray.com/core/common/errors"
@@ -22,7 +23,7 @@ func ReadAllToMultiBuffer(reader io.Reader) (MultiBuffer, error) {
 			mb.Append(b)
 		}
 		if err != nil {
-			if errors.Cause(err) == io.EOF {
+			if errors.Cause(err) == io.EOF || errors.Cause(err) == os.ErrClosed {
 				return mb, nil
 			}
 			mb.Release()
diff --git a/common/errors/errors.go b/common/errors/errors.go
index 3e5e09425..daac515d2 100644
--- a/common/errors/errors.go
+++ b/common/errors/errors.go
@@ -3,6 +3,7 @@ package errors // import "v2ray.com/core/common/errors"
 
 import (
 	"context"
+	"os"
 	"strings"
 
 	"v2ray.com/core/common/log"
@@ -162,12 +163,27 @@ func Cause(err error) error {
 	if err == nil {
 		return nil
 	}
+L:
 	for {
-		inner, ok := err.(hasInnerError)
-		if !ok || inner.Inner() == nil {
-			break
+		switch inner := err.(type) {
+		case hasInnerError:
+			if inner.Inner() == nil {
+				break L
+			}
+			err = inner.Inner()
+		case *os.PathError:
+			if inner.Err == nil {
+				break L
+			}
+			err = inner.Err
+		case *os.SyscallError:
+			if inner.Err == nil {
+				break L
+			}
+			err = inner.Err
+		default:
+			break L
 		}
-		err = inner.Inner()
 	}
 	return err
 }
diff --git a/common/platform/ctlcmd/ctlcmd.go b/common/platform/ctlcmd/ctlcmd.go
index 28b5fd250..45611c1ca 100644
--- a/common/platform/ctlcmd/ctlcmd.go
+++ b/common/platform/ctlcmd/ctlcmd.go
@@ -16,7 +16,7 @@ import (
 func Run(args []string, input io.Reader) (buf.MultiBuffer, error) {
 	v2ctl := platform.GetToolLocation("v2ctl")
 	if _, err := os.Stat(v2ctl); err != nil {
-		return nil, err
+		return nil, newError("v2ctl doesn't exist").Base(err)
 	}
 
 	errBuffer := &buf.MultiBuffer{}
@@ -30,19 +30,19 @@ func Run(args []string, input io.Reader) (buf.MultiBuffer, error) {
 
 	stdoutReader, err := cmd.StdoutPipe()
 	if err != nil {
-		return nil, err
+		return nil, newError("failed to get stdout from v2ctl").Base(err)
 	}
 	defer stdoutReader.Close()
 
 	if err := cmd.Start(); err != nil {
-		return nil, err
+		return nil, newError("failed to start v2ctl").Base(err)
 	}
 
 	var content buf.MultiBuffer
 	loadTask := func() error {
 		c, err := buf.ReadAllToMultiBuffer(stdoutReader)
 		if err != nil {
-			return err
+			return newError("failed to read config").Base(err)
 		}
 		content = c
 		return nil