Been happening for the past three or four days. F1 menu when I try to reconnect says:

"facepunch_connector_missingfeatureimplementat ion"

Admin side says VAC auth timeout

No, I'm not hacking. I admin a popular community server in legacy. It happens on both my Steam accounts. I've restarted everything. I've uninstalled Rust and Steam. No antivirus. No firewall. It possibly started when I updated Windows 8.1 recently. Rebooted my router. Nothing works. After I get kicked, I have to wait another 10 minutes before I can log back in. Then the cycle starts all over.