Server log:

[16:12:50] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:12:54] [Main Thread/WARN] [tML]: Silently Caught Exception:
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
at BossChecklist.PlayerAssist.Hurt(Boolean pvp, Boolean quiet, Double damage, Int32 hitDirection, Boolean crit) in BossChecklist\PlayerAssist.cs:line 219
at Terraria.ModLoader.PlayerLoader.Hurt(Player player, Boolean pvp, Boolean quiet, Double damage, Int32 hitDirection, Boolean crit) in tModLoader\Terraria\ModLoader\PlayerLoader.cs:line 321
at DMD<Terraria.Player::Hurt>(Player this, PlayerDeathReason damageSource, Int32 Damage, Int32 hitDirection, Boolean pvp, Boolean quiet, Boolean Crit, Int32 cooldownCounter)
at Terraria.MessageBuffer.GetData(Int32 start, Int32 length, Int32& messageType) in tModLoader\Terraria\MessageBuffer.cs:line 3198
at Terraria.NetMessage.CheckBytes(Int32 bufferIndex) in tModLoader\Terraria\NetMessage.cs:line 2202
at Terraria.Netplay.UpdateServerInMainThread() in tModLoader\Terraria\Netplay.cs:line 64
at Terraria.Main.DoUpdate(GameTime& gameTime) in tModLoader\Terraria\Main.cs:line 12729
at Terraria.Main.Update(GameTime gameTime) in tModLoader\Terraria\Main.cs:line 12618
at Terraria.Main.DedServ_PostModLoad(Boolean& reloadMods) in tModLoader\Terraria\Main.cs:line 4608
at Terraria.Main.DedServ() in tModLoader\Terraria\Main.cs:line 4144
at Terraria.Program.LaunchGame_(Boolean isServer) in tModLoader\Terraria\Program.cs:line 231
at Terraria.Program.LaunchGame(String[] args, Boolean monoArgs) in tModLoader\Terraria\Program.cs:line 194
at MonoLaunch.<>c__DisplayClass2_0.<Main>b__0() in tModLoader\Terraria\MonoLaunch.cs:line 65
at System.Threading.Thread.StartCallback()

[16:12:54] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:12:54] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:12:56] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:12:57] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:12:58] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer
[16:13:00] [Main Thread/WARN] [Terraria]: Error on message Terraria.MessageBuffer