Thanks for the trick needed to apply the update (amazing that Sandisk hasn’t fixed the ISO images…). That allowed me to update my (failing) v2 128GB Ultra+ drive. After installing, I booted into a DVD of Knoppix, and saw the new firmware version.
I was doing this because my 1-week-old (though sitting on a shelf for a year or two) SSD suddenly started locking up when touching certain sectors. I had (painfully!) copied all but a few hundred MB (at a guess) with ddrescue to another drive (since the SSD locked up hard on touching a bad sector, I had to continually save the ddrescue state, do a hard reboot (restart didn’t un-bork the SSD), then run again. I quickly got 99%, but then got into areas where I’d get 0 to a few hundred KB before hitting a bad set. After 50-some iterations of this (and looking at hundreds and hundreds more, even before trying to dissect the failed blocks (4 to 64K each)), I checked for a firmware update. There was one!
The update (this one) was supposed to improve error handling and such. Great, just what I needed (I hoped)! With this thread, I got it updated successfully! Then I powered down, reattached other drives, and powered-on. Hung probing SATA-1 (which it had done all along occasionally). power-cycle - same. 25 power-cycles later, I gave up. 
Ironically I installed it to replace a failed rotating disk with a head crash (only 5 files affected, only 1 interesting and that was just an IMAP mailbox file, so all the data lives on a server). But now I get to reclone the data, and re-do all the cleanup. And unfortunately I moved a bunch of email (when cleaning up) to local folders on the SSD… That’s all gone forever now. (I did preserve the attempted clone of the SSD, but there’s no working directory structure there… a recovery program might be able to dig out the files, if they don’t have holes in them, maybe.)
