Having the same problem.
FIrst it gave me the "update" message that's mentioned elsewhere.
So I'm forced to: download and install the "line 6 monkey", register the unit for the benefit of line 6 database who now has all my personal data, and buy 2 midi cables (that I will never use again) to download the update. Which is all very annoying for a guitar pedal, mind you. No other company gives you this hassle for a multi fx. But ok, I do it.
When it was finishing downloading, I got an unspecified error, and now the unit is showing the blank screen mentioned in this thread.
Again, I don't really see the point of having to "update" a guitar pedal. This is incredibly frustrating.
Very very dissapointed with all this - is anybody going to offer a solution? Or is Line 6 determined to acquire a bad reputation in this highly competitive field?