Please follow the steps below for troubleshooting. 
 
1.Remove all USB devices from the monitor except the USB-C cable or 
    USB upstream cable (USB TypeA to TypeB cable) and the calibrator that 
    connects to the PC/NB and the monitor.
2.Uninstall the current version of the PME program and all of the 
    calibration programs
3.Download the latest version of PME from BenQ's official website and 
    re-install it 
4.The Key Step: When installing PME software, keep the USB-C or USB 
    upstream cable (USB TypeA to TypeB cable) connected to the monitor 
    and PC/NB directly, and make sure all drivers are correctly installed 
    during the installation.
5.Reboot the PC/NB and open PME to check if it can work.
6.If the error message persists, unplug and re-plug the USB upstream 
    cable (USB TypeA to TypeB cable) or replace a new one.
 
If the issue still exists, please contact BenQ local service for further assistance.