I got the following message when updating, via lucy, from 19.07.7 to 21.02.1
Device ubnt-erx not supported by this image Supported devices: ubnt,edgerouter-x ubnt-erx ubiquiti,edgerouterx - Image version mismatch: image 1.1, device 1.0. Please wipe config during upgrade (force required) or reinstall. Reason: Config cannot be migrated from swconfig to DSA Image check failed.
The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform.
With this guide, you can make a backup archive of your router. You can then either restore the backup archive back to the router or open up the backup archive tar file and read the configuration files in there. Note that, by default, it will not back up your additional packages you added either via Luci or opkg in ssh. You must follow step #1 in the guide for that.
That 'another one' link in my previous reply has marked his topic as solved. It seems he has answered my 'initramfs-factory > sysupgrade' method question.
About Backup and Restore link, I think all my setups are included in the backup, because the list under configuration menu charges all the submenus of lucy.
I restored some backups in the past and they always loaded the custom setup.
Isn´t it? @jow , Is it possible that the problem would be solved soon?
But if the issue is only the DSA conversion you may be able to just set aside the network config and proceed. Whether on the device itself, or in a backup / restore.