I have in Installation Blockly ,and doing step by here.
now I roslaunch robot_blockly robot_blockly.launch ,and I get the feedback that down.
... logging to /root/.ros/log/b05a6c90-e917-11e6-955e-b827eb94dc37/roslaunch-erle-brain-2-1892.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.
started roslaunch server http://erle-brain-2:43283/
* /rosdistro: kinetic
* /rosversion: 1.12.4
core service [/rosout] found
process[robot_blockly_backend-1]: started with pid 
process[robot_blockly_webserver-2]: started with pid 
Traceback (most recent call last):
File "/root/blockly_ws/install_isolated/lib/robot_blockly/scripts/robot_blockly_backend.py", line 51, in
from crab_msgs.msg import apm_imu
ImportError: No module named 'crab_msgs'
[robot_blockly_backend-1] process has died [pid 1910, exit code 1, cmd /root/blockly_ws/install_isolated/lib/robot_blockly/scripts/robot_blockly_backend.py _name:=robotblockly_backend _log:=/root/.ros/log/b05a6c90-e917-11e6-955e-b827eb94dc37/robotblockly_backend-1.log].
log file: /root/.ros/log/b05a6c90-e917-11e6-955e-b827eb94dc37/robot_blockly_backend-1*.log
So I think it's failing , Any help appreciated.