have ROS melodic and I have been trying to use the hokuyo lidar, but rviz shows the aforementioned error. All the solutions elsewhere were for from to fixed frame transform errors, in the GlobalOptions also I have changed the FixedFrame option from [FixedFrame] to 'robot_footprint', but still the problem is present.

The tf tree is shown below

and the error is rviz is

Please help if possible.