Hello everybody, I'm following the tutorials and now I'm trying to run in two different terminals

roslaunch rrbot_gazebo rrbot_world.launch
roslaunch rrbot_description rrbot_rviz.launch

But every time that I run the second command I've got this message error in the first command terminal.

[gazebo-1] process has died [pid 5648, exit code 139, cmd /opt/ros/hydro/lib/gazebo_ros/gzserver /home/joao/my_ws/src/gazebo_ros_demos/rrbot_gazebo/worlds/rrbot.world __name:=gazebo __log:=/home/joao/.ros/log/94591c54-1d71-11e4-bd60-c4850825495a/gazebo-1.log]. 

log file: /home/joao/.ros/log/94591c54-1d71-11e4-bd60-c4850825495a/gazebo-1*.log

Anyone knows how to solve this problem?

I'm running gazebo 1.9.3 and Ros-hydro.

Thanks