Dropping connection due to Datatype mismatch

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Hi All,

Kindly help me in finding a fix for this.

I am playing a rosbag which has 5 topics. I want to create a new node and subscribe to one of topic from the rosbag.

I am getting the below error when I try to subscribe to the topic.

 [ERROR] [XXXXX]: Client [/A] wants topic /B to have datatype/md5sum [std_msgs/String/], but our version has [visualization_msgs/MarkerArray/]. Dropping connection.

Looks like the data type from bag file is visualization_msgs/MarkerArray/, how would I make modifications in code so that subscription happens without any issue ?

Subscriber Code given below:

 #include "ros/ros.h"
 #include "std_msgs/String.h"
 #include <visualization_msgs/Marker.h>

 void chatterCallback(const std_msgs::String::ConstPtr& msg)
 {
  ROS_INFO("Control has come inside the function");
  ROS_INFO("I heard: [%s]", msg->data.c_str());
 }

 int main(int argc, char **argv)
 {
  ros::init(argc, argv, "listener");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("my_topic", 1000, chatterCallback);
  ROS_INFO("Initiated the ROS node and subscriber");
  ros::spin();
  return 0;
 }

Updating the question:

I am trying the same code outside and inside the docker.

Outside the docker: Fixed the error by changing the datatype of the parameter in call back to const visualization_msgs::MarkerArray::ConstPtr& msg

But inside the docker the issue remains the same. The control doesn't come inside the callback function at all.

Waiting 0.2 seconds after advertising topics.../rrrrrr/platform/ros/ros_comm/roscpp/src/libros/publication.cpp:629 Publication::validateHeader() [ERROR] [1535722434.248608746]: Client [/my_c] wants topic /topic to have datatype/md5sum [visualization_msgs/MarkerArray/90da67007c26525f655c1c269094e39f], but our version has [visualization_msgs/MarkerArray/d155b9ce5188fbaf89745847fd5882d7]. Dropping connection.

Thank you, KK