Argh! Thought I had bought the right thing.
I also am a victim of the microSD card defeating firmware update, and I am ticked. I bought this so that I could upgrade the card when needed - the extention was suppose to be for music and data. However, now that the card doesn’t work, I just have to use it as an over-priced flash drive. So I thought I’d plug in the express and rev up ye olde sansaUpdater, and lo and behold, it wouldn’t let me even connect - I kept getting the “you’re in MTP mode, switch to MSC mode” message. Which I did. Fourteen times. And uninstalled and reinstalled the updater software three times from 2 different download links from the SanDisk website. Sigh.
So, after being ready to just send the darn thing flying across the room, I did a little search and rescue mission.