Hi All,

I am running ROS Melodic n Ubuntu 18.04 LTS version. I am working RVIZ web to display RVIZ web page. I am encoutring a error which I am unable to resolve, Please help me.

I wrote following launch file

<launch>
    <!-- ROS Web Server Launching -->
    <include file="$(find rosbridge_server)/launch/rosbridge_websocket.launch" >
       <arg name="port" value="8080"/>
       <!-- <arg name="port" value="9090" /> -->
       <!-- <arg name="address" value="0.0.0.0" /> -->
    </include>

    <node name="web_video_server" pkg="web_video_server" type="web_video_server">
        <param name="port" value="11315" />
    </node>


    <!-- rviz web server -->
    <include file= "$(find rvizweb)/launch/rvizweb.launch" >
    </include>

</launch>

When I roslaunch the file I get following output

venna@venna:~$ roslaunch web_gui webgui.launch
... logging to /home/venna/.ros/log/813b9000-a58f-11ea-af2b-a0d37a83da1f/roslaunch-venna-3458.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://venna:33109/

SUMMARY
========

PARAMETERS
 * /rosapi/params_glob: [*]
 * /rosapi/services_glob: [*]
 * /rosapi/topics_glob: [*]
 * /rosbridge_websocket/address: 0.0.0.0
 * /rosbridge_websocket/authenticate: False
 * /rosbridge_websocket/bson_only_mode: False
 * /rosbridge_websocket/delay_between_messages: 0
 * /rosbridge_websocket/fragment_timeout: 600
 * /rosbridge_websocket/max_message_size: None
 * /rosbridge_websocket/params_glob: [*]
 * /rosbridge_websocket/port: 8080
 * /rosbridge_websocket/retry_startup_delay: 5
 * /rosbridge_websocket/services_glob: [*]
 * /rosbridge_websocket/topics_glob: [*]
 * /rosbridge_websocket/unregister_timeout: 10
 * /rosbridge_websocket/use_compression: False
 * /rosbridge_websocket/websocket_external_port: None
 * /rosbridge_websocket/websocket_ping_interval: 0
 * /rosbridge_websocket/websocket_ping_timeout: 30
 * /rosdistro: melodic
 * /rosversion: 1.14.5
 * /rvizweb/global_config: <...>
 * /web_video_server/port: 11315

NODES
  /
    interactive_marker_proxy (interactive_marker_proxy/proxy)
    rosapi (rosapi/rosapi_node)
    rosbridge_websocket (rosbridge_server/rosbridge_websocket)
    roswww (roswww/webserver.py)
    tf2_web_republisher (tf2_web_republisher/tf2_web_republisher)
    web_video_server (web_video_server/web_video_server)

auto-starting new master
process[master]: started with pid [3469]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to 813b9000-a58f-11ea-af2b-a0d37a83da1f
process[rosout-1]: started with pid [3500]
started core service [/rosout]
process[rosbridge_websocket-2]: started with pid [3510]
process[rosapi-3]: started with pid [3511]
ERROR: cannot launch node of type [web_video_server/web_video_server]: Cannot locate node of type [web_video_server] in package [web_video_server]. Make sure file exists in package path and permission is set to executable (chmod +x)
ERROR: cannot launch node of type [tf2_web_republisher/tf2_web_republisher]: Cannot locate node of type [tf2_web_republisher] in package [tf2_web_republisher]. Make sure file exists in package path and permission is set to executable (chmod +x)
process[roswww-6]: started with pid [3512]
process[interactive_marker_proxy-7]: started with pid [3513]
[INFO] [1591184637.881351]: Rosapi started
2020-06-03 17:13:57+0530 [-] Log opened.
2020-06-03 17:13:57,941 - roswww - INFO - roswww : # of packages : 255
2020-06-03 17:13:57,941 - roswww - INFO - roswww : Weg Page root : /
2020-06-03 17:13:58,050 - roswww - INFO - roswww : Initialised
2020-06-03 17:13:58,051 - roswww - INFO - roswww : Attempting to start webserver on port 8080
2020-06-03 17:13:58,051 - roswww - INFO - roswww : Webserver successfully started on port 8080
2020-06-03 17:13:58+0530 [-] registered capabilities (classes):
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.call_service.CallService
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.advertise.Advertise
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.publish.Publish
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.subscribe.Subscribe
2020-06-03 17:13:58+0530 [-]  - <class 'rosbridge_library.capabilities.defragmentation.Defragment'>
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.advertise_service.AdvertiseService
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.service_response.ServiceResponse
2020-06-03 17:13:58+0530 [-]  - rosbridge_library.capabilities.unadvertise_service.UnadvertiseService
2020-06-03 17:13:58+0530 [-] Traceback (most recent call last):
2020-06-03 17:13:58+0530 [-]   File "/home/venna/gui_ws/src/rosbridge_suite/rosbridge_server/scripts/rosbridge_websocket", line 48, in <module>
2020-06-03 17:13:58+0530 [-]     from rosbridge_server import ClientManager
2020-06-03 17:13:58+0530 [-]   File "/home/venna/gui_ws/devel/lib/python2.7/dist-packages/rosbridge_server/__init__.py", line 34, in <module>
2020-06-03 17:13:58+0530 [-]     exec(__fh.read())
2020-06-03 17:13:58+0530 [-]   File "<string>", line 5, in <module>
2020-06-03 17:13:58+0530 [-]   File "/home/venna/gui_ws/src/rosbridge_suite/rosbridge_server/src/rosbridge_server/client_mananger.py", line 35, in <module>
2020-06-03 17:13:58+0530 [-]     from rosbridge_msgs.msg import ConnectedClient, ConnectedClients
2020-06-03 17:13:58+0530 [-] ImportError: No module named msg
[rosbridge_websocket-2] process has died [pid 3510, exit code 1, cmd /home/venna/gui_ws/src/rosbridge_suite/rosbridge_server/scripts/rosbridge_websocket __name:=rosbridge_websocket __log:=/home/venna/.ros/log/813b9000-a58f-11ea-af2b-a0d37a83da1f/rosbridge_websocket-2.log].
log file: /home/venna/.ros/log/813b9000-a58f-11ea-af2b-a0d37a83da1f/rosbridge_websocket-2*.log