On this page here: Camera Calibration | Stereolabs
I think this line
CalibrationParameters calibration_params = zed.getCameraInformation()->calibration_parameters;
should be replaced with
CalibrationParameters calibration_params = zed.getCameraInformation().camera_configuration.calibration_parameters;
because the current variant is deprecated.
relevant part in struct CameraInformation:
SL_DEPRECATED("Use camera_configuration.calibration_parameters instead")
CalibrationParameters calibration_parameters; /**< \deprecated see CameraConfiguration::calibration_parameters, Intrinsic and Extrinsic stereo parameters for rectified/undistorded images (default).*/