skeleton_markers markers_from_tf.launch isn't working

[me2george]

when i ran roslaunch skeleton_markers markers_from_tf.launch , i met following mistakes. I am new ros users ,it very confused me

[INFO] [WallTime: 1512315359.407959] Initializing Skeleton Markers Node...
Traceback (most recent call last):
File "/home/mzy/catkin_ws/src/rbx1/skeleton_markers/nodes/markers_from_tf.py", line 142, in
SkeletonMarkers()
File "/home/mzy/catkin_ws/src/rbx1/skeleton_markers/nodes/markers_from_tf.py", line 69, in init
frames = [f for f in tf_listener.getFrameStrings() if f.startswith('head_')]
File "/opt/ros/indigo/lib/python2.7/dist-packages/tf/listener.py", line 98, in getFrameStrings
return [p for p, _ in data.items()]
AttributeError: 'list' object has no attribute 'items'
[markers_from_tf-3] process has died [pid 2204, exit code 1, cmd /home/mzy/catkin_ws/src/rbx1/skeleton_markers/nodes/markers_from_tf.py __name:=markers_from_tf __log:=/home/mzy/.ros/log/a58f5b96-d83f-11e7-9a2b-45de7d56a8a2/markers_from_tf-3.log].
log file: /home/mzy/.ros/log/a58f5b96-d83f-11e7-9a2b-45de7d56a8a2/markers_from_tf-3*.log