I believe I had a similar problem. I modified the launchSitl script as follows:
##Launch a SITL instance
##/home/david/anaconda2/envs/dpp/bin/dronekit-sitl copter --home=44.5013,-88.0622,0,180 &
~/courseRoot/apm/ardupilot/build/sitl/bin/arducopter -S -I0 --home=44.5013,-88.0622,0,180 --model “+” --speedup 1 --defaults /home/david/courseRoot/apm/ardupilot/Tools/autotest/default_params/copter.parm &
I know this doesn’t specifically identify what was wrong, but it a least allowed me to get past the error.