Error for project

Hi, I got an error when doing “roslaunch realrobotlab main.launch” for part1 of the project of ROS basics.

error below:

Warning [parser.cc:723] Can not find the XML attribute ‘version’ in sdf XML tag for model: triangular_prism_direccion_obligada. Please specify the SDF protocol supported in the model configuration file. The first sdftag in the config file will beused
[ERROR] [1640657448.493862017,1.963000000]: GetModelState: model [moving_cube] does not exist
[ERROR] [1640657448.524110676,1.994000000]: GetModelState: model [moving_cube] does not exist
[ERROR] [1640657448.527436271,1.998000000]: GetModelState: model [moving_cube] does not exist

Hi, welcome to the community!

Those errors do not stop the simulation from running. If you let the terminal load and then open Gazebo icon in the bottom of your screen, you will be able to see the simulation.

Thanks~I will try it now.