Excavator edit

Enything what i do i got error with plugin when i save a file GatherManager.json

I got that error in logs: what is below. 

When i just use option edit and dont change anything just save got same issue. 

(08:49:34) | Failed to initialize plugin 'GatherManager v2.2.75' (InvalidCastException: Invalid cast from 'System.Double' to 'System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=*.*.*.*, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Object, mscorlib, Version=*.*.*.*, Culture=neutral, PublicKeyToken=b77a5c561934e089]]'.)
  at System.Convert.DefaultToType (System.IConvertible value, System.Type targetType, System.IFormatProvider provider) [0x00269] in <eae584ce26bc40229c1b1aa476bfa589>:0 
  at System.Double.System.IConvertible.ToType (System.Type type, System.IFormatProvider provider) [0x00000] in <eae584ce26bc40229c1b1aa476bfa589>:0 
  at System.Convert.ChangeType (System.Object value, System.Type conversionType, System.IFormatProvider provider) [0x0021b] in <eae584ce26bc40229c1b1aa476bfa589>:0 
  at System.Convert.ChangeType (System.Object value, System.Type conversionType) [0x0000c] in <eae584ce26bc40229c1b1aa476bfa589>:0 
  at Oxide.Plugins.GatherManager.GetConfigValue[T] (System.String category, System.String setting, T defaultValue) [0x00040] in <9ac1c44a70a1416a8ff20fda9aab5df6>:0 
  at Oxide.Plugins.GatherManager.LoadConfigValues () [0x0008a] in <9ac1c44a70a1416a8ff20fda9aab5df6>:0 
  at Oxide.Plugins.GatherManager.Init () [0x00000] in <9ac1c44a70a1416a8ff20fda9aab5df6>:0 
  at Oxide.Plugins.GatherManager.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00038] in <9ac1c44a70a1416a8ff20fda9aab5df6>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <60c318df79ed41688ea59335e48d61ad>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <12678b905a6d43c3a9cc366104306651>:0 
  at Oxide.Core.Plugins.CSPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x00043] in <12678b905a6d43c3a9cc366104306651>:0
(08:49:34) | Unloaded plugin Gathering Manager v2.2.75 by Mughisi
(08:49:34) | No previous version to rollback plugin: GatherManager
  "Messages": {
    "Dispensers": "Resource Dispensers",
    "Excavators": "Excavators",
    "HelpText": "/gather - Shows you detailed gather information.",
    "HelpTextAdmin": "To change the resources gained by gathering use the command:\r\ngather.rate <type:dispenser|pickup|quarry|survey> <resource> <multiplier>\r\nTo change the amount of resources in a dispenser type use the command:\r\ndispenser.scale <dispenser:tree|ore|corpse> <multiplier>\r\nTo change the time between Mining Quarry gathers:\r\nquarry.tickrate <seconds>",
    "HelpTextMiningQuarrySpeed": "Time between Mining Quarry gathers: {0} second(s).",
    "HelpTextPlayer": "Resources gained from gathering have been scaled to the following:",
    "HelpTextPlayerDefault": "Default values.",
    "HelpTextPlayerGains": "Resources gained from {0}:",
    "InvalidArgumentsDispenserType": "Invalid arguments supplied! Use dispenser.scale <dispenser:tree|ore|corpse> <multiplier>",
    "InvalidArgumentsGather": "Invalid arguments supplied! Use gather.rate <type:dispenser|pickup|quarry|survey> <resource> <multiplier>",
    "InvalidArgumentsMiningQuarrySpeed": "Invalid arguments supplied! Use quarry.rate <time between gathers in seconds>",
    "InvalidDispenser": "{0} is not a valid dispenser. Check gather.dispensers for a list of available options.",
    "InvalidMiningQuarrySpeed": "You can't set the speed lower than 1 second!",
    "InvalidModifier": "Invalid modifier supplied! The new modifier always needs to be bigger than 0!",
    "InvalidResource": "{0} is not a valid resource. Check gather.resources for a list of available options.",
    "MiningQuarries": "Mining Quarries",
    "ModifyDispenser": "You have set the resource amount for {0} dispensers to x{1}",
    "ModifyMiningQuarrySpeed": "The Mining Quarry will now provide resources every {0} seconds.",
    "ModifyResource": "You have set the gather rate for {0} to x{1} from {2}.",
    "ModifyResourceRemove": "You have reset the gather rate for {0} from {1}.",
    "NotAllowed": "You don't have permission to use this command.",
    "Pickups": "pickups",
    "SurveyCharges": "Survey Charges"
  "Options": {
    "ExcavatorBeltSpeedMax": 0.1,
    "ExcavatorResourceModifiers": {},
    "ExcavatorResourceTickRate": 5.0,
    "ExcavatorTimeForFullResources": 120.0,
    "GatherDispenserModifiers": {},
    "GatherResourceModifiers": {
      "*": 10.0
    "MiningQuarryResourceTickRate": 10.0,
    "PickupResourceModifiers": 2.0,
    "QuarryResourceModifiers": {},
    "SurveyResourceModifiers": {}
  "Settings": {
    "ChatPrefix": "Gather Manager",
    "ChatPrefixColor": "#008000ff"

The PickupResourceModifiers should be someting like.
"PickupResourceModifiers": { "*": 2.0 },