sympl-firewall: does not play nicely with iptables-persistent
You can get in an odd state if you don't have any v4 DNS resolvers and have iptables-persistent installed, where it will eventually fail to bring up the IPv6 address on the server, after timing out, and sympl-fireall will fail in an odd was, meaning the server acts unusually.
Adding iptables-persistent (and friends) to the conflicts list should prevent this.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information