Your message is woefully thin

What version of Calibre? On what OS?
(latest Calibre knows about newer FW. This is an issue for those stuck on old OS that can't run newer Calibre)
Aura1 or Aura2? Is the Aura FW updated? In Calibre, the driver has a tickbox to 'support newer FW'. in most cases this works (but updating is still the best)