I get this error in console:

[ServerArmour] MR.fli*** (7656119*******) at 41.68.***.*** has been approved to connect
...
[Error] Failed to call hook 'CanUserLogin' on plugin 'ServerArmour v0.0.91' (InvalidOperationException: Sequence contains no matching element) at System.Linq.Enumerable.First[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) [0x00011] in :0 at Oxide.Plugins.ServerArmour.IsBanned (System.String steamid) [0x00024] in <81638aba290d49d9983d878f1dc6d01a>:0 at Oxide.Plugins.ServerArmour.AssignGroupsAndBan (Oxide.Core.Libraries.Covalence.IPlayer player) [0x00077] in <81638aba290d49d9983d878f1dc6d01a>:0 at Oxide.Plugins.ServerArmour.CanUserLogin (System.String name, System.String id, System.String ip) [0x0000d] in <81638aba290d49d9983d878f1dc6d01a>:0 at Oxide.Plugins.ServerArmour.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00873] in <81638aba290d49d9983d878f1dc6d01a>:0 at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <33f7c42a56934dae8ec04b11017dce31>:0 at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in :0 at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0​
...
[ServerArmour] MR.fli**** (7656119*********) connected from 41.68.***.***
...
[ServerArmour] MR.flik (7656119*********) disconnected
14:55 [Info] [Welcomer]  MR.fl**** left the server (Kicked: Cheat Detected!)
14:55 [Info] [ServerArmour] Player MR.flik (7656119*********) was kicked, reason: Cheat Detected!
14:55 [Info] [ServerArmour] MR.fl****has ban cached, now updating.
14:56 [Info] [ServerArmour] 41.68.***.***:7656119*********:MR.fl**** tried to connect. But the connection was rejected due to him being banned, Reason: Cheat Detected!

This only happens to some players

Thank you, will investigate this issue

Merged post

This should be fixed in the new version.