Jack does not start

Hello, I have just installed UbuntuStudio 14.04 in my laptop ASUS X554L.

Sound works (youtube, for example), but jack does not. When I press Start button in QjackCtl I get this (I appologize, some messages are in Spanish, I can translate them if needed):

19:34:30.775 Patchbay desactivada.

19:34:30.778 Reiniciar estadísticas.
19:34:30.783 Cambios en las conexiones ALSA.
19:34:30.796 D-BUS: Disponible (org.jackaudio.service aka jackdbus).
Caot coect to server socket err = No existe el archivo o el directorio
Caot coect to server request chael
jack server is not ruing or caot be started
19:34:30.804 Cambió el gráfico de conexiones ALSA.
(qjackctl:2500): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:2500): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
19:34:47.682 D-BUS: El servidor JACK no puede iniciarse. Disculpa
Caot coect to server socket err = No existe el archivo o el directorio
Caot coect to server request chael
jack server is not ruing or caot be started
(qjackctl:2500): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:2500): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
Tue Apr 5 19:34:47 2016: Starting jack server...
Tue Apr 5 19:34:47 2016: JACK server starting in realtime mode with priority 10
Tue Apr 5 19:34:47 2016: ERROR: caot register object path "/org/freedesktop/ReserveDevice1/Audio0": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Tue Apr 5 19:34:47 2016: ERROR: Failed to acquire device name : Audio0 error : A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Tue Apr 5 19:34:47 2016: ERROR: Audio device hw:0 caot be acquired...
Tue Apr 5 19:34:47 2016: ERROR: Caot initialize driver
Tue Apr 5 19:34:47 2016: ERROR: JackServer::Open failed with -1
Tue Apr 5 19:34:47 2016: ERROR: Failed to open server
Tue Apr 5 19:34:49 2016: Saving settings to "/home/ajh/.config/jack/conf.xml" ...
19:34:53.720 No puede conectarse al servidor JACK como cliente. - La operación global falló. - No puede conectarse al servidor. Por favor revise la ventana de mensajes para mas información.
Caot coect to server socket err = No existe el archivo o el directorio
Caot coect to server request chael
jack server is not ruing or caot be started
19:34:58.848 D-BUS: El servidor JACK no puede iniciarse. Disculpa
Tue Apr 5 19:34:58 2016: Starting jack server...
Tue Apr 5 19:34:58 2016: JACK server starting in realtime mode with priority 10
Caot coect to server socket err = No existe el archivo o el directorio
Caot coect to server request chael
jack server is not ruing or caot be started
Tue Apr 5 19:34:58 2016: ERROR: caot register object path "/org/freedesktop/ReserveDevice1/Audio0": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Tue Apr 5 19:34:58 2016: ERROR: Failed to acquire device name : Audio0 error : A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Tue Apr 5 19:34:58 2016: ERROR: Audio device hw:0 caot be acquired...
Tue Apr 5 19:34:58 2016: ERROR: Caot initialize driver

Tue Apr 5 19:34:58 2016: ERROR: JackServer::Open failed with -1
Tue Apr 5 19:34:58 2016: ERROR: Failed to open server
Tue Apr 5 19:35:00 2016: Saving settings to "/home/ajh/.config/jack/conf.xml" ...
19:35:08.870 No puede conectarse al servidor JACK como cliente. - La operación global falló. - No puede conectarse al servidor. Por favor revise la ventana de mensajes para mas información.
Caot coect to server socket err = No existe el archivo o el directorio
Caot coect to server request chael
jack server is not ruing or caot be started