I have been suffering the same exact issue for the last month or so. What I found is that the drivers aren't loading properly, in that the system will recognize a device is plugged in and sometimes the name of the device but it will not determine the correct driver. To check if you are having the same issue as me do the following:
1. click command + x
2.select device manger
3. plug in any usb device (usb drive might be best)
4. check if unknown device appears
This will look like a yellow triangle next to a device in the other category. If this happens click on the device and select update driver. If automatic update doesn't work select let me choose my own driver. Then select the option below browse, like select from list or something. Scroll down to storage volumes (if you plugged in a usb drive) and select generic storage volume. This should allow you to use the drive.
I currently do this with all usb drivers and am currently looking for a more permanent fix. Obviously select the device type that you plugged in not storage volume every time. Please post if you find a permanent solution or if this helps.