I use several Firewall Groups. All of them begin with letters of the alphabet.
I know that I cannot use a name ending in a number.
When I rename them to begin with a number, the entire system locks up very quickly . A reboot does not resolve anything. I need to login to the console and restore a config backup.
Is this a bug or an undocumented constraint on the names?
I should say that I am using a fully updated version 24.4
I should have added a third possibility: user error.
Indeed the mistake was mine. I mistakenly applied some groups to both a vlan interface and its underlying ethernet. This was 'locking' the system.