I restored the DHCP file from version 24.10 to version 25.12.2, and then the router crashed

Installing and Using OpenWrt
1

A RAX3000Me run at 24.10.5 i backedup the config.
then, upgrade to 25.12.2 . restored the config and the router
crash..

The change is that the original backup file contained many static IPs of devices. Here is an example: When I manually added them in the new version, I encountered a problem: the underscore "_" is not accepted in the new version.

config host
	option name 'midea_ca_0667'
	option ip '192.168.1XX.1XX'
	option mac '04:D6:F4:XX:XX:XX'
2

sed 's/_/./g' /etc/config/dhcp

3

See https://datatracker.ietf.org/doc/html/rfc1035#section-2.3.1, underscores aren't valid characters in names. Change them to dashes.

4

My question is why these names can be backed up in version 24.10. :joy:

However, I've now deleted and modified all the underscores. I didn't understand why the restored backup file wasn't working until I tried this.