J9 is connected to the adapter board, only play a download role, here is a place where customers may need with the installation of the shell, because after the installation of the shell J10 will be blocked.
J6 is the capacitive screen wiring place, J11 is the resistive screen wiring place. From your photo, your screen line connected to J11 should be resistive screen.
About your problem when downloading, please upload an image so I can see what the problem is.
I can only offer you two solutions now.
1. when copying a new VT file to the U disk, delete the previous file first to make sure there is only one VT file in the U disk.
2. Formatting the U disk and then try to copy the file again and download it into the LCD.