(09:38:32) | Failed to run a 0.20 timer in 'ServerArmour v0.0.99' (ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index)
at System.Linq.Enumerable.ElementAt[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Int32 index) [0x0007b] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
at Oxide.Plugins.ServerArmour+<CheckOnlineUsers>c__AnonStorey2.<>m__0 () [0x0005a] in <d32708bcc23c4dda80afbd8e031dd432>:0
at Oxide.Core.Libraries.Timer+TimerInstance.FireCallback () [0x00018] in <ac41dd3599754d448b8c218b34645820>:0
(09:38:32) | Failed to run a 1.00 timer in 'ServerArmour v0.0.99' (ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index)
at System.Linq.Enumerable.ElementAt[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Int32 index) [0x0007b] in <351e49e2a5bf4fd6beabb458ce2255f3>:0
at Oxide.Plugins.ServerArmour+<CheckLocalBans>c__AnonStorey3.<>m__0 () [0x00000] in <d32708bcc23c4dda80afbd8e031dd432>:0
at Oxide.Core.Libraries.Timer+TimerInstance.FireCallback () [0x00018] in <ac41dd3599754d448b8c218b34645820>:0

Was there anyone online at the time? 
Please redownload 0.0.99, as there was a hotfix

thx. it works