My '22 FX couldn't be updated through the app as well, I got the same error.
It's my understanding that Zero will discontinue use of their app and move all functions over to the Next Gen App.
The bike's firmware needed to be updated for it to communicate and work with the Next Gen App properly.
I hadn't planned on doing an update since everything was working great and I haven't had a single issue.
But, I made an appointment anyways and took it to my dealer. They flashed the newest firmware versions and everything still works fine.
I almost want to say the motor sounds quieter, but it's probably just me.
The Next Gen App can connect to my bike and everything seems to work. When I checked the firmware section the app tells me the bike needs an update and to contact the dealer.
The new versions currently installed on the bike are MBB: 37 and BMS: 44
Dealer told me those are the latest versions, but Zero's website doesn't appear to be up to date with that info.
I'm sure they are the latest versions for the FX, but maybe they aren't available for an update through the app yet?
This is the message from Zero about the matter. I copied it from the link posted below on the Elektroroller Forum
Hello Zero Owners,
In about one week, NextGen app version 2.8.0 will be released with full functionality for ALL Zero models. This is a particularly important update for Cypher II Zero owners (FX, FXE, S, DS, DSR) to pay attention to.
If you own a Cypher II model and have not updated the firmware on your bike, now is the time. The older legacy Zero app will be permanently retired August 31, 2023, and in order to be eligible for future firmware updates through the new NextGen app, you will need to have the most recent app version (2.7.2) installed. Failure to complete this prior to August 31 means you will be required to visit a local dealer to manually update your MBB/BMU/BMS firmware to the latest version to ensure future firmware update eligibility through the NextGen app.
This newest app version addresses the following bug fix and concerns:
• Restores firmware update functionality for Cypher II bikes (with eligible firmware) from the app (explained above).
• Significant improvement to firmware updates for Cypher III bikes.
• Improvements to Cypher upgrade systems.
• Updated urls of Privacy Policy in stores.
• Refinements in custom ride modes.
• Bug fixes and improvements.
This app version will go live for both Android and iOS users.
Please contact us at ownersupport@zeromotorcycles.com if you have any questions.
Thank you for your continued support!
https://www.elektroroller-forum.de/viewtopic.php?f=12&t=37309