I was concerned as well after receiving this cryptic error message on a brand new unit and relieved it was merely a FW update.
Just a note for those updating: Took an hour or so and then my webapp actually hung up on the following message:
Progress: The machine must be restarted to enable the firmware settings. Please wait until the restart process is complete.
After an hour or so of this I was suspicious - had seen the blue progress light flashing during update - obviously normal - and now had been solid blue for a long time after what I assumed to be a restart. Knowing that it normally doesn't take that long I opened a new tab, typed in the IP, and loaded another page with the webapp. This showed the updated firmware version and no mention of updating in progress. NASNav2 also indicated it was on the new FW and the old error message was gone. After calling tech support this AM they confirmed the webapp just wasn't updated after the power reboot, but I was good to go and could close the old tab which was hung up on the restart.
Just so no one else is waiting into perpetuity for something that's done figured worth mentioning.
