I managed to install by redownloading the ISO, repeating all the steps (verifying, burning, etc). On the second (!) attempt of trying to install using the same flash drive, it succeeded. The first time, it gave me some other error.
So...trying the same thing multiple times may not be insanity after all? -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to qubes-users@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/896ffe0d-36f8-4189-b08d-2313734dd74e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.