I checked already all items here in the community, but did not found appropriate solution: I make a backup of my configuration of my one-and-only router and immediately try to restore it, then I get this message:
"The selected backup file is not compatible with this device, please choose another file."
I do not want to workaround by USB-stick or SCP, and I do not like to do factory-reset since I'm not fully sure I get my backup-file restored/applied. So just I'd like this to work as expected ;-)
( Creating and restoring users-default-config works. )