Cannot export to a toshiba usb device

For my daily backups i've switched from a relatively small USB stick to a 1 terabyte Toshiba USB powered device.
(My backups are not huge but i really like having a big device for the backups and anything else i want to put on it).

When i try to "export to (this) USB Flash Drive" the NEXT button is grayed out.

I'm guessing that Opus doesn't like this as a flash drive ?

It may not be recognised as a USB device for some reason.

You can export to any folder on any drive if you tick the "use as a dongle" option with a USB flash drive. As long as the flash drive is inserted, the files themselves can be anywhere.