I've been using m0n0wall 1.2b7 for a few weeks.

I setup captive portal for a single user, which worked fine.

A few days later I decided to setup a guest account. After I added the 
user the system completely died.

When ever I went to the webadmin I got the following error:
XML error: not well-formed (invalid token) at line 460

I restarted the system and nothing worked. I couldn't even ping the 
system. So I did a reset of the configuration locally on the system and 
re setup the configuration.

So the system is running again, I didn't need to reinstall m0n0wall. 
Just reset the configuration.

Any ideas what happened?

-- 
Michael Dale
mdale at dalegroup dot net