Error with connecting to database

Failed to initialize plugin 'BetterStatistics v1.2.1' (InvalidCastException: Object cannot be cast from DBNull to other types.)
  at System.DBNull.System.IConvertible.ToInt32 (System.IFormatProvider provider) [0x00000] in <f98723dd4586469db5213ec59da723ca>:0 
  at System.Convert.ToInt32 (System.Object value, System.IFormatProvider provider) [0x00003] in <f98723dd4586469db5213ec59da723ca>:0 
  at MySql.Data.MySqlClient.Driver.LoadCharacterSets (MySql.Data.MySqlClient.MySqlConnection connection) [0x00079] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at MySql.Data.MySqlClient.Driver.Configure (MySql.Data.MySqlClient.MySqlConnection connection) [0x00060] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at MySql.Data.MySqlClient.MySqlConnection.Open () [0x00198] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at Oxide.Plugins.BetterStatistics.Loaded () [0x00069] in <4e6d6b28f670467f91e9bb92299d55f3>:0 
  at Oxide.Plugins.BetterStatistics.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0014a] in <4e6d6b28f670467f91e9bb92299d55f3>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <206a0f2c6ee141f38e2ad549cde44d70>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Plugins.CSharpPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x000cf] in <206a0f2c6ee141f38e2ad549cde44d70>:0 
Exception while invoking event handler (FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.)
  at System.Text.StringBuilder.AppendFormatHelper (System.IFormatProvider provider, System.String format, System.ParamsArray args) [0x000f9] in <f98723dd4586469db5213ec59da723ca>:0 
  at System.String.FormatHelper (System.IFormatProvider provider, System.String format, System.ParamsArray args) [0x00023] in <f98723dd4586469db5213ec59da723ca>:0 
  at System.String.Format (System.String format, System.Object[] args) [0x00020] in <f98723dd4586469db5213ec59da723ca>:0 
  at Oxide.Core.Logging.Logger.CreateLogMessage (Oxide.Core.Logging.LogType type, System.String format, System.Object[] args) [0x0007e] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Core.Logging.Logger.Write (Oxide.Core.Logging.LogType type, System.String format, System.Object[] args) [0x00000] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Core.Logging.CompoundLogger.Write (Oxide.Core.Logging.LogType type, System.String format, System.Object[] args) [0x00015] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Core.OxideMod.LogWarning (System.String format, System.Object[] args) [0x00006] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Core.MySql.Libraries.MySql.OnRemovedFromManager (Oxide.Core.Plugins.Plugin sender, Oxide.Core.Plugins.PluginManager manager) [0x0006d] in <021a1dba6a754e42a6cc7771fdfee190>:0 
  at Oxide.Core.Event+Callback`2[T1,T2].Call (T1 arg0, T2 arg1) [0x0000c] in <beb2b64691c64e2b95b99491bd85442c>:0 
Unloaded plugin Better Statistics v1.2.1 by Billy Joe
No previous version to rollback plugin: BetterStatistics
o.load BetterStatistics
There is already an open connection, using existing connection instead...
Failed to initialize plugin 'BetterStatistics v1.2.1' (InvalidOperationException: The connection is already open.)
  at MySql.Data.MySqlClient.ExceptionInterceptor.Throw (System.Exception exception) [0x00039] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at MySql.Data.MySqlClient.MySqlConnection.Throw (System.Exception ex) [0x0000a] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at MySql.Data.MySqlClient.MySqlConnection.Open () [0x00014] in <8d7380b3d3cf4bd8be324c584f371b44>:0 
  at Oxide.Plugins.BetterStatistics.Loaded () [0x00069] in <4e6d6b28f670467f91e9bb92299d55f3>:0 
  at Oxide.Plugins.BetterStatistics.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0014a] in <4e6d6b28f670467f91e9bb92299d55f3>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <206a0f2c6ee141f38e2ad549cde44d70>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <beb2b64691c64e2b95b99491bd85442c>:0 
  at Oxide.Plugins.CSharpPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x000cf] in <206a0f2c6ee141f38e2ad549cde44d70>:0 
Unloaded plugin Better Statistics v1.2.1 by Billy Joe
No previous version to rollback plugin: BetterStatistics

IS there a way to fix this?? ive been trying to setup the plugin for a couple days now and have not found a fix for this issue

if needed can give access to server and database

Any help??