can't get sound in qsampler/linuxsampler

can't get sound in qsampler/linuxsampler when i try to set up a channel i got errar message: 08:45:27.025 New Channel setup... 08:45:37.876 Channel 0 added. 08:45:37.969 Channel 0 Audio driver: JACK. 08:45:37.981 Channel 0 MIDI driver: JACK. 08:45:37.992 Channel 0 MIDI port: 0. 08:45:38.002 Channel 0 MIDI channel: 0. 08:45:39.012 Channel 0 lscp_load_engine: Timeout during receive operation (errno=-4) 08:45:41.043 Channel 0 lscp_load_instrument: Timeout during receive operation (errno=-4) 08:45:42.056 Channel 0 lscp_set_channel_midi_map: Failure during flush timeout operation (errno=-4) 08:45:42.067 Channel 0 Some channel settings could not be set. Sorry. anybody can help???