@@ -224,7 +224,7 @@ func (s *containerRouter) postContainersKill(ctx context.Context, w http.Respons

 		// to keep backwards compatibility.

 		version := httputils.VersionFromContext(ctx)

 		if version.GreaterThanOrEqualTo("1.20") || !isStopped {

-			return fmt.Errorf("Cannot kill container %s: %v", name, err)

+			return fmt.Errorf("Cannot kill container %s: %v", name, utils.GetErrorMessage(err))

 		}

 	}

@@ -462,7 +462,7 @@ func (s *containerRouter) wsContainersAttach(ctx context.Context, w http.Respons

 		}

 		if err := s.backend.ContainerWsAttachWithLogs(containerName, wsAttachWithLogsConfig); err != nil {

-			logrus.Errorf("Error attaching websocket: %s", err)

+			logrus.Errorf("Error attaching websocket: %s", utils.GetErrorMessage(err))

 		}

 	})

 	ws := websocket.Server{Handler: h, Handshake: nil}

@@ -11,6 +11,7 @@ import (

 	"github.com/docker/docker/api/server/httputils"

 	"github.com/docker/docker/api/types"

 	"github.com/docker/docker/pkg/stdcopy"

+	"github.com/docker/docker/utils"

 	"golang.org/x/net/context"

 )

@@ -45,7 +46,7 @@ func (s *containerRouter) postContainerExecCreate(ctx context.Context, w http.Re

 	// Register an instance of Exec in container.

 	id, err := s.backend.ContainerExecCreate(execConfig)

 	if err != nil {

-		logrus.Errorf("Error setting up exec command in container %s: %s", name, err)

+		logrus.Errorf("Error setting up exec command in container %s: %s", name, utils.GetErrorMessage(err))

 		return err

 	}

@@ -112,7 +113,7 @@ func (s *containerRouter) postContainerExecStart(ctx context.Context, w http.Res

 		if execStartCheck.Detach {

 			return err

 		}

-		logrus.Errorf("Error running exec in container: %v\n", err)

+		logrus.Errorf("Error running exec in container: %v\n", utils.GetErrorMessage(err))

 	}

 	return nil

 }