Check my post above the one you answered -
Try different cable, make sure your using the same USB port as when it did work.
- - - -
We are going to be seeing a lot of this I think -
Bluetooth speakers come with the "power only" USB cables -
So if you plug in the Kindle with the speaker's USB cable, suddenly the Kindle is "broke".

Not really "broke" it only looks that way.
And Amazon did not think to add that caution to the page on the limitations of VV over Bluetooth.