exploration stack demo error [closed]

edit

hi everyone

I try to use exploration stack which consists of some demos in explore_stage package like explore.launch, but when i launch this file i see this error:

NODES
  /

explore (explore/explore)  
fake_localize (tf/static_transform_publisher)   
move_base (move_base/move_base)  
    stage (stage/stageros)

auto-starting new master  
process[master]: started with pid [8766]  
ROS_MASTER_URI=http://localhost:11311   

setting /run_id to e37832f4-2f53-11e4-aa10-a4db30c4fe2c   
process[rosout-1]: started with pid [8779]   
started core service [/rosout]    
process[stage-2]: started with pid [8793]    
process[fake_localize-3]: started with pid [8808]    
process[move_base-4]: started with pid [8822]    
process[explore-5]: started with pid [8840]    
[ INFO] [1409299808.926411941]: Subscribed to Topics: base_scan    
 [Loading /opt/ros/fuerte/stacks/bosch_common/bosch_worlds/maze.world][Include segway.inc][Include sick.inc]     [Image "../bosch_maps/maze.png"]     

err: Model type laser not found in model typetable (/tmp/buildd/ros-fuerte-stage-1.6.6/debian/ros-fuerte-stage/opt/ros/fuerte/stacks/stage/build/stage/libstage/world.cc CreateModel)    
err: Unknown model type laser in world file. (/tmp/buildd/ros-fuerte-stage-1.6.6/debian/ros-fuerte-stage/opt/ros/fuerte/stacks/stage/build/stage/libstage/world.cc CreateModel)    

[ INFO] [1409299809.217661849]: Subscribed to Topics: base_scan    
[stage-2] process has died [pid 8793, exit code 1, cmd /opt/ros/fuerte/stacks/stage/bin/stageros /opt/ros/fuerte/stacks/bosch_common/bosch_worlds/maze.world __name:=stage __log:=/home/mohammad/.ros/log/e37832f4-2f53-11e4-aa10-a4db30c4fe2c/stage-2.log].     
log file: /home/mohammad/.ros/log/e37832f4-2f53-11e4-aa10-a4db30c4fe2c/stage-2*.log

i am a new user in ROS and i dont know what is the problem. I appreciate if someone could help me. Thanks:))