Subscribing to multiple Image ROS topics in VM Parallels

edit

I'm subscribing to multiple ROS topics of Image data type coming from a system fitted with 5 stereo cameras. Subscribing to just 1 camera topic works flawlessly but if extended to multiple topics I get the following error and no google search helped me with this, hence the question turned to ROS forum.

Note : I'm running this framework on VM Parallels on Mac.

"WARNING: QApplication was not created in the main() thread. Segmentation fault (core dumped)"