After today's update, an error appeared in the console and the server does not start.

Server Exception: Connection Queue
MissingMethodException: System.Collections.Generic.IEnumerator`1 ListHashSet`1.GetEnumerator()
Server Exception: Player Update
MissingMethodException: System.Collections.Generic.IEnumerator`1 ListHashSet`1.GetEnumerator()
Server Exception: Connection Queue
MissingMethodException: System.Collections.Generic.IEnumerator`1 ListHashSet`1.GetEnumerator()
Server Exception: Player Update
MissingMethodException: System.Collections.Generic.IEnumerator`1 ListHashSet`1.GetEnumerator()
Server Exception: Connection Queue

This would mean that your server isn't fully updated.

The server was completely updated, oxide was the latest version. The problem was with the NoSteam plugin, after uninstalling it, the server started up and works fine.