stage error in indigo

edit

Hi, I'm new to ROS but I try to follow tutorials at wiki.ros and I cannot work out this issue with stage. Following this tutorial http://wiki.ros.org/stage/Tutorials/I... I came to Wander Controller. I downloaded package from github and did few changes according to this discussion https://answers.ros.org/question/3397...

ad1. I have changed all "laser" to "ranger" ad2. I added "z" and "theta" positions

I'm still getting this error message though:

[Loading stage/stage_controllers/world/roomba-wander.world]
warn: lookup of model name roomba.ranger:1: no matching name (/tmp/binarydeb/ros-indigo-stage-4.1.1/libstage/world.cc GetModel)
warn: Model roomba.ranger:1 not found (/tmp/binarydeb/ros-indigo-stage-4.1.1/libstage/model.cc GetChild)
Segmentation fault (core dumped)

Any help? Thanks!