With Windows 10 sometimes USB storage units such as Bluray or DVDs are not detected properly even though they are plug and play compatible. This is the case with my external Asus BD/DVD.
So here’s a possible solution and it doesn’t even need a reboot:
Open up the Device Manager and check for Initio Combo Device and under that the Initio Default Controller and select Properties. Select the Driver tab and Update Driver.
You then choose Select from the computer – and then usually again Select from list on the computer.
There you will find the Initio and USB Mass storage driver. Select the USB Mass Storage driver and that should do it for plug and play devices.