I spent the last several hours trying to find out what's going on and I've given up. I just finished deleting ALL files, reinstalling RustDedicated (linux), and threw on Oxide. It's still not working. The console outputs that it recognizes if I unload/load a plugin by uploading/deleting plugin files, but it never shows up on the server list, and you can't connect directly to it or use RCON (all things that worked just fine for the last 5 months). This is on a hosted dedicated server, and I've ensured my server isn't on the blacklist.

To replicate, install a brand new copy of Rust and install the latest oxide. Create an identity, restart.

Latest server log, for reference: https://puu.sh/ItcfG/c4d170e45c.log

From what I've seen, these commands:

zombie.population
halloween.murdererpopulation
Halloween.scarecrowpopulation

These three should be disabled, set to 0

We use those for roaming NPCs/zombies. Been set for over a month. Did they brick those from working?

Also worth noting - Not sure where the '3's come from. Our config is set as below:
halloween.enabled true
halloween.murdererpopulation 40
halloween.scarecrowpopulation 0
halloween.scarecrow_body_dmg_modifier 0.5

NPCs were overhauled with this Rust update.

Well, I feel absolutely retarded now.

I'm sure your suggestion fixed the original problem, but when I restarted my reserver it re-enabled firewalld which was preventing the game service from receiving connections.

We are good to go on the plugin-less version, and halloween/zombie variables set to 0.