Getting "ArgumentNullException" on updating database

[metrosound]

Everytime I run the log window show "Updating game database 80832 => 84172" then followed with an red error message "ArgumentNullException: Argument cannot be null.
Parameter name: value"

But it doing just fine when I disable auto update database

below is the full log

Initialize engine version: 5.6.2f1 (a2913c821e27)
GfxDevice: creating device client; threaded=1
Direct3D:
Version: Direct3D 11.0 [level 11.0]
Renderer: NVIDIA GeForce GTX 770 (ID=0x1184)
Vendor: NVIDIA
VRAM: 3072 MB
Driver: 23.21.13.8813
Begin MonoManager ReloadAssembly
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Assembly-CSharp.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Assembly-CSharp.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.UI.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.UI.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.Networking.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\UnityEngine.Networking.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Gma.System.MouseKeyHook.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Gma.System.MouseKeyHook.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\MumbleLink-CSharp-GW2.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\MumbleLink-CSharp-GW2.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\MumbleLink-CSharp.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\MumbleLink-CSharp.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Newtonsoft.Json.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\Newtonsoft.Json.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Drawing.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Drawing.dll into Unity Child Domain
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Windows.Forms.dll (this message is harmless)
Loading E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Windows.Forms.dll into Unity Child Domain

• Completed reload, in 0.047 seconds
  Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Core.dll (this message is harmless)
  Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.dll (this message is harmless)
  Initializing input.

Input initialized.

desktop: 1920x1080 60Hz; virtual: 2732x1848 at -404,-768
Initialized touch support.

UnloadTime: 1.209146 ms
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Xml.dll (this message is harmless)
Platform assembly: E:\Guild Wars 2\addons\AugTyr-0.4\AugTyr_Data\Managed\System.Data.dll (this message is harmless)
Setting up 4 worker threads for Enlighten.
Thread -> id: 3da0 -> priority: 1
Thread -> id: 3fec -> priority: 1
Thread -> id: 1168 -> priority: 1
Thread -> id: 3854 -> priority: 1
ArgumentNullException: Argument cannot be null.
Parameter name: value
at Newtonsoft.Json.Linq.JToken.EnsureValue (Newtonsoft.Json.Linq.JToken value) [0x00000] in :0
at Newtonsoft.Json.Linq.JToken.op_Explicit (Newtonsoft.Json.Linq.JToken value) [0x00000] in :0
at GameDatabaseHolder+c__Iterator1.MoveNext () [0x00000] in :0
at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in :0

(Filename: Line: -1)