Hi,all I install ros-by-exanple-indigo code on my computer.And I prepare to test fake robot simulator.However,Once I run the .launch file there will be a mistake in rviz.See follow.

run command:

 roslaunch rbx1_bringup fake_turtlebot.launch

then run

rosrun rviz rviz -d 'rospack find rbx1_nav' /sim.rviz

then there's a mistake in rviz, Global Status ：error

fixed frame :fixed frame [map] do not exist