@ApoorvThapliyal : the problem (Error message: "set_position_target_local_ned: coordinate frame 0 unsupported") appeared in QGC after updating VOXL SDK from 1.5.0 to 1.6.3.
The error blocked me from being able to use QGC to calibrate or arm the drone. Stopping and restarting voxl-vision-hub solved the problem.
For now I'm using voxl-vision-hub as it comes on SDK 1.6.3 (no changes yet) and have not made changes to the .conf file (yet).