insmod: /mnt/usb/sda1/usbmon.ko: No such file or directory

This error message indicates that the kernel module "usbmon.ko" could not be loaded because it was not found in the specified directory "/mnt/usb/sda1/". This could happen if the file is missing or if the path is incorrect. You should check the path and make sure that the file exists in that location. If the file is missing, you may need to reinstall the module or download it from a trusted source.