As a follow-up, if you're trying to hack rviz by adding new messages to it, you need to add the messages in a separate package. rviz builds its own swig-based Python module that prevents the ROS python data classes from loading. C++ messages will work, but Python will not due to the way Python defines modules. - Ken On Tue, Jun 8, 2010 at 4:05 PM, Ken Conley wrote: > Hi Hao, > > I'm not sure what you mean by "rostopic echo *" > > Your error message is odd because there is no such message > "rviz/SelectionMessage". It would be helpful if you provided more details. > > - Ken > > > On Tue, Jun 8, 2010 at 3:54 PM, Hao Dang wrote: > >> Hello all, >> >> I met a problem when I use "rostopic echo *" on a topic which I built, >> ROS complained and said "Cannot load message class for >> [rviz/SelectionMessage]. Are your messages built?". But when I wrote >> a dedicated listener which subscribed to this topic, I can get the >> information of the published messages to this topic. Does anybody >> know why? By the way, "rostopic list" can list the topic and >> "rostopic info" can also get the information of the topic. >> >> Thank you! >> >> Hao >> _______________________________________________ >> ros-users mailing list >> ros-users@code.ros.org >> https://code.ros.org/mailman/listinfo/ros-users >> > >