Robot Behaviour

When loading map from Library, status is stuck at 'Halting Localization'.

Loading a map from the library requires laser scan data. Check your robot is publishing laser scan data by running a rostopic echo /scan. (Replace /scan with your robot topic.)

Unable to localise the map

Check your tf tree to make sure there is only 1 unbroken connection from map to base_link. rosrun rqt_tf_tree rqt_tf_tree.
Also, please check your amcl node (for 2D) is running and publishing. rosnode list | grep amcl and rosnode info /amcl.