Upgraded to 8.1, now /etc/security failing

[russell_mcmanus%yahoo.com@localhost]

I upgraded to 8.1 on top of a 6 install using the standard install tools.

I'm getting a message like this in the email sent to root in the daily
insecurity output email:

mtree: unknown group `_rtadvd'
mtree: failed at line 417 of the specification

I started reading /etc/security but this is a relatively complicated
program.  Anything jump out that I should look at / fix?

Thanks
Russ