macbook pro wont see external dvd player

hi , i am running High Sierra 10.13.6 on my mac Book Pro (MID 2015) i cant seem to get it to "see' any external devices. i have tried my external DVD Drive and also my external hard drive. both work on other devices. i have checked the boxes in preferences to show them on the desktop. I have checked the USB ports and they are working. i have also tried with the firewall on and off.

can anyone help? i 'm gong nuts!