Web request callback raised an exception (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.ServerArmour.IsBadIp (Oxide.Plugins.ServerArmour+ISAPlayer isaPlayer) [0x00023] in <b924643ecf024d149faf625836fab956>:0

  at Oxide.Plugins.ServerArmour+<_webCheckPlayer>c__AnonStorey1.<>m__0 (System.Int32 code, System.String response) [0x00a4b] in <b924643ecf024d149faf625836fab956>:0

please try version 0.8.0 https://umod.org/plugins/ServerArmour.cs?version=0.8.0&branch=develop