You have to make sure that the MoveIt cofiguration (I'm assuming you're trying to configure MoveIt here, seeing your other questions) corresponds to whatever namespaces and names your action server(s) is (are) using.
That can sometimes be a bit difficult to figure out, but a simple way to get that information (in lieu of a command line actionlib tool) is something like:
rostopic list | grep -i goal
That should provide you with a list of online action servers.
If you've only got your robot driver (or ros_control or gazebo_ros_control stack) running, you should probably see only one or two results.
One of those will be the FollowJointTrajectory action server (you can use rostopic info /name/of/the/action/topic to find out).
Now use that name in your MoveIt controller configuration file.
For more information, see the Low Level Controllers page in the MoveIt documentation. That should make things more clear. Pay attention to the Debugging Information section: it contains an explanation of the differences between the name and action_ns fields, which typically confuse people.
Edit:
these are the active action servers:
/execute_trajectory/goal
This is probably the one you need (but this is a guess, as I don't know how you've setup your system).
/uvbot_v1/arm_controller/follow_joint_trajectory/goal
This is most likely not a server, but MoveIt's client that has created a publisher for that topic (as part of its action client). But as no one is listening, you get the error message that you already showed.
is there a conflict btw execute_trajectory and follow_joint_trajectory
I don't understand your question.
