Comment 7 for bug 1448404

I also see this with a fresh install of Ubuntu 15.04 on my netbook (Toshiba NB550D). Installation was a straight-forward "use whole disk for Ubuntu, and encrypt everything". On boot, screen goes black. Entering the encryption password "blind" continues the boot successfully (login screen appears and everything's fine). The workaround of switching terminals with Ctrl+Alt+F1 then Ctrl+Alt+F7 also works, causing the password prompt to appear.

I haven't tried fiddling with crypttab as I seem to recall that's the file that records what to do with mounted volumes at boot (though I presume it'll actually get used in the creation of an initrd in this case as the file itself wouldn't be readable until the encrypted volume is mounted ... Catch-22 and all that). Anyway, fiddling with it sounds like a bad idea all round so I'll stick with the terminal switch workaround for now.