After posting the same advice over and over and over throughout the last years (and for several times just during the last hours), I decided to post this here, so I can just link to it (it's also missing in any official Line 6 documentation, at least in a direct, straight ahead form).
So, your update to whatever firmware failed? The following steps helped TONS of people over the last years, so give them a try.
Note: I am assuming that you've backed up your HX family devic