Fail loading model://gazebo about dolly HOT 3 CLOSED

[INFO] [launch]: All log files can be found below /home/raf/.ros/log/2020-12-29-21-59-53-138763-block-9096
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [gzserver-1]: process started with pid [9098]
[INFO] [gzclient --verbose  -2]: process started with pid [9100]
[INFO] [dolly_follow-3]: process started with pid [9104]
[INFO] [rviz2-4]: process started with pid [9106]
[gzclient --verbose  -2] Gazebo multi-robot simulator, version 11.1.0
[gzclient --verbose  -2] Copyright (C) 2012 Open Source Robotics Foundation.
[gzclient --verbose  -2] Released under the Apache 2 License.
[gzclient --verbose  -2] http://gazebosim.org
[gzclient --verbose  -2]
[gzserver-1] Gazebo multi-robot simulator, version 11.1.0
[gzserver-1] Copyright (C) 2012 Open Source Robotics Foundation.
[gzserver-1] Released under the Apache 2 License.
[gzserver-1] http://gazebosim.org
[gzserver-1]
[rviz2-4] [INFO] [1609232393.935624263] [rviz2]: Stereo is NOT SUPPORTED
[rviz2-4] [INFO] [1609232393.935745373] [rviz2]: OpenGl version: 3 (GLSL 1.3)
[rviz2-4] [INFO] [1609232393.960239584] [rviz2]: Stereo is NOT SUPPORTED
[gzserver-1] [Msg] Waiting for master.
[gzserver-1] [Msg] Connected to gazebo master @ http://127.0.0.1:11345
[gzserver-1] [Msg] Publicized address: 192.168.2.121
[gzserver-1] Error [parser.cc:749] Could not find model.config or manifest.xml for the model
[gzserver-1] Error [parser.cc:749] Could not find model.config or manifest.xml for the model
[gzserver-1] Error [parser.cc:397] File [] doesn't exist.
[gzserver-1] Error Code 1 Msg: Unable to read file[]
[gzserver-1] Error Code 8 Msg: Error reading element <world>
[gzserver-1] Error Code 8 Msg: Error reading element <sdf>
[gzserver-1] [Err] [Server.cc:407] Unable to read sdf file[dolly_city.world]
[gzserver-1] [Wrn] [Server.cc:351] Falling back on worlds/empty.world
[gzclient --verbose  -2] [Msg] Waiting for master.
[gzclient --verbose  -2] [Msg] Connected to gazebo master @ http://127.0.0.1:11345
[gzclient --verbose  -2] [Msg] Publicized address: 192.168.2.121
[gzclient --verbose  -2] [Wrn] [Publisher.cc:136] Queue limit reached for topic /gazebo/default/user_camera/pose, deleting message. This warning is printed only once.
^C[WARNING] [launch]: user interrupted with ctrl-c (SIGINT)
[dolly_follow-3] [INFO] [1609232481.261107167] [rclcpp]: signal_handler(signal_value=2)
[rviz2-4] [INFO] [1609232481.261735609] [rclcpp]: signal_handler(signal_value=2)
[INFO] [dolly_follow-3]: process has finished cleanly [pid 9104]
[gzserver-1] [Wrn] [Publisher.cc:136] Queue limit reached for topic /gazebo/default/physics/contacts, deleting message. This warning is printed only once.
[INFO] [rviz2-4]: process has finished cleanly [pid 9106]
[ERROR] [gzserver-1]: process has died [pid 9098, exit code -2, cmd 'gzserver dolly_city.world      --verbose                                                             -s libgazebo_ros_init.so   -s libgazebo_ros_factory.so       '].
[gzserver-1]
[gzserver-1]
[ERROR] [gzclient --verbose  -2]: process has died [pid 9100, exit code -2, cmd 'gzclient --verbose  '].
[gzclient --verbose  -2]
[gzclient --verbose  -2]