Im getting.... 

(10:59:23) | Failed to call hook 'OnUserChat' on plugin 'Keywords v1.0.0' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Game.Rust.Libraries.Player.Message (BasePlayer player, System.String message, System.String prefix, System.UInt64 userId, System.Object[] args) [0x00038] in <40394e96ea4a461497fd902b2ed74f3b>:0
at Oxide.Game.Rust.Libraries.Covalence.RustPlayer.Message (System.String message, System.String prefix, System.Object[] args) [0x00000] in <40394e96ea4a461497fd902b2ed74f3b>:0
at Oxide.Game.Rust.Libraries.Covalence.RustPlayer.Message (System.String message) [0x00008] in <40394e96ea4a461497fd902b2ed74f3b>:0
at Oxide.Plugins.Keywords.OnUserChat (Oxide.Core.Libraries.Covalence.IPlayer player, System.String message, System.String[] args) [0x000a9] in <efb0bf5d7c5d420fbf1e2d318aa2dc9b>:0
at Oxide.Plugins.Keywords.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00038] in <efb0bf5d7c5d420fbf1e2d318aa2dc9b>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <4452f821def6406d834e4149849fe7ea>:0

thats if "Notify configured players in chat (true/false)" is true

Merged post

Otherwise.... Awesome rewrite mate

Were the player using the keyword and all of the configured players online at the time?

ah... not all configed players were, 1 of 2 were online

It should have still been handled, but might have added that after the public version. I'll check and make sure.