chapter 2 face tracker error

[Silerqin]

Hi, I have issue when I press roslaunch face_tracker_pkg start_tracking.launch . Here is my error:

setting /run_id to 751b6be4-f033-11ea-87d5-00044be66635
process[rosout-1]: started with pid [3605]
started core service [/rosout]
process[usb_cam-2]: started with pid [3612]
process[face_tracker-3]: started with pid [3613]
[ INFO] [1599391441.873770485]: Successfully Loaded tracking parameters
[ INFO] [1599391442.050595318]: using default calibration URL
[ INFO] [1599391442.052396196]: camera calibration URL: file:///home/ubuntu/.ros/camera_info/head_camera.yaml
[ INFO] [1599391442.052672714]: Unable to open camera calibration file [/home/ubuntu/.ros/camera_info/head_camera.yaml]
[ WARN] [1599391442.052751414]: Camera calibration file /home/ubuntu/.ros/camera_info/head_camera.yaml not found.
[ INFO] [1599391442.052820165]: Starting 'head_camera' (/dev/video0) at 640x480 via mmap (yuyv) at 30 FPS
OpenCV Error: Bad argument (Invalid pointer to file storage) in cvGetRootFileNode, file /build/opencv-XDqSFW/opencv-3.2.0+dfsg/modules/core/src/persistence.cpp, line 926
terminate called after throwing an instance of 'cv::Exception'
  what():  /build/opencv-XDqSFW/opencv-3.2.0+dfsg/modules/core/src/persistence.cpp:926: error: (-5) Invalid pointer to file storage in function cvGetRootFileNode

[face_tracker-3] process has died [pid 3613, exit code -6, cmd /home/ubuntu/ros_robotics_project_ws/devel/lib/face_tracker_pkg/face_tracker_node __name:=face_tracker __log:=/home/ubuntu/.ros/log/751b6be4-f033-11ea-87d5-00044be66635/face_tracker-3.log].
log file: /home/ubuntu/.ros/log/751b6be4-f033-11ea-87d5-00044be66635/face_tracker-3*.log

Can I know how to solve this error?

[therobocademy]

Can you check the following thread @Silerqin

https://answers.ros.org/question/294359/opencv-3-runtime-error-invalid-pointer-to-file-storage-cv_bridge-third-party-library/

[Silerqin]

@therobocademy Thank you for your reply. I found that I am using opencv 4.1.1. Now should I install opencv3.2 to solved this error?