My Oxide is up to date
Oxide.Rust Version: 2.0.6140
[CSharp] Started Oxide.Compiler v*.*.*.* successfully
(00:24:38) | Error while compiling MasterKey: 'HashSet<PlayerNameID>' does not contain a definition for 'RemoveAll' and no accessible extension method 'RemoveAll' accepting a first argument of type 'HashSet<PlayerNameID>' could be found (are you missing a using directive or an assembly reference?) | Line: 232, Pos: 54