Default configuration script failure in 7.12.1

I have bought an RB5009 a couple of days ago and I’m still in the learning phase. It came with ROS 7.8 (I can’t remember exactly) and I upgraded it just out of the box.
I’ve now tried to reset it to default configuration to start with a clean device. After reboot I get on terminal this error:

system,error,critical error while running default configuration script: bad command name wireless (line 39…)
I think the error is connected to :

:while ([/interface wireless print count-only]...

From terminal I can see that the command is not recognized (should it be /interface wifiwave2..?)
The script aborts so the device is almost not configured at all (no firewall rules, no dhcp server..).
Is there a way I can reload the default configuration?