Hi Mr. Hassaan, sorry for the late reply.
In your case, the probably reason might be the damage of the USB-disk or the USB interface.
To check if it is the USB disk reason, you can test it with another device like PC. If you can save the file in the FAT32 USB disk, then it should be OK to use on the display.
To check if it is the USB interface issue you can check with the USB external board. In the accessories package there should be a external USB board for downloading. You can check with that board to see if it is OK