Running on 64 bit Windows with 32 GB RAM 
Version: v1.14.7 (Stable)1/26/2021 7:37:03 PM: Critical error occurred
System.Exception: Don't know how to instantiate item of class 'ItemRepairKit' did you forget to register a mapping?
   at Vintagestory.Common.ClassRegistry.CreateItem(String itemClass)
   at Vintagestory.Common.ItemTypeNet.ReadItemTypePacket(_sMxJhSpeKM9FyG8JUoVJmSXeu5 packet, IWorldAccessor world, ClassRegistry registry)
   at Vintagestory.Client.NoObf.GeneralPacketHandler.HandleServerAssets(_SgnnqebBH0BM984ItS5vhDzSB2c packet)
   at Vintagestory.Client.NoObf.ClientMain.ExecuteMainThreadTasks(Single deltaTime)
   at _Ji8ZCYdD03AdlbF434eaGgnZqbbA._h7dO1pJXJpGwhthMPDN9E21LMTB(Single )
   at _QXfAdKxrJ1KaNtwiV64JU2IvnpC._cl7z8c5uEEaIF1fo0XdijiZbRYk(Single )
   at _QXfAdKxrJ1KaNtwiV64JU2IvnpC._peV5mb21IaSJTAYBddj4gA99BDo(Single )
   at Vintagestory.Client.NoObf.ClientPlatformWindows.window_RenderFrame(Object sender, FrameEventArgs e)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at OpenTK.GameWindow.RaiseRenderFrame(Double elapsed, Double& timestamp)
   at OpenTK.GameWindow.DispatchRenderFrame()
   at OpenTK.GameWindow.Run(Double updates_per_second, Double frames_per_second)
   at _03wQBzfCnykaMLiRGgbQzrKOcn3._QN2fpVgRVBDOLs27GIkkdMlxeKf(_a9AJZVMB0wcgfRPD19VvLtZCbaX , String[] )
   at _NdjU5BXvKkfOW2d88pNMbEAjE1q._QN2fpVgRVBDOLs27GIkkdMlxeKf(ThreadStart )
-------------------------------

Event Log, last 3 entries
==================================
{ TimeGenerated = 1/16/2021 10:29:32 PM, Site = , Source = .NET Runtime, Message = Application: Vintagestory.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: exception code c0020001, exception address 00007FFC18AD3B29
Stack:
 }
{ TimeGenerated = 11/19/2020 3:24:32 PM, Site = , Source = .NET Runtime, Message = Application: Vintagestory.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: exception code c0020001, exception address 00007FFF1DA13B29
Stack:
   at System.Environment._Exit(Int32)
   at System.Environment._Exit(Int32)
   at System.Environment.Exit(Int32)
   at _tbDNSZpN0b4WGkPbXXfou7PhsQl._4FaQHZNbeHKn9WINUsvqvFV8i9T()
   at Vintagestory.API.Client.GuiElementTextButton.OnMouseUpOnElement(Vintagestory.API.Client.ICoreClientAPI, Vintagestory.API.Client.MouseEvent)
   at Vintagestory.API.Client.GuiElement.OnMouseUp(Vintagestory.API.Client.ICoreClientAPI, Vintagestory.API.Client.MouseEvent)
   at Vintagestory.API.Client.GuiElementTextButton.OnMouseUp(Vintagestory.API.Client.ICoreClientAPI, Vintagestory.API.Client.MouseEvent)
   at Vintagestory.API.Client.GuiComposer.OnMouseUp(Vintagestory.API.Client.MouseEvent)
   at _VisI2OeWzgjAMuHLDUPaKaN5Lds._6J0Ioc1Jsh7Nj2siLiS88rTI5Ze(Vintagestory.API.Client.MouseEvent)
   at Vintagestory.Client.NoObf.ClientPlatformWindows.Mouse_ButtonUp(System.Object, OpenTK.Input.MouseButtonEventArgs)
   at System.EventHandler`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Invoke(System.Object, System.__Canon)
   at System.EventHandler`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Invoke(System.Object, System.__Canon)
   at OpenTK.Platform.Windows.WinGLNative.WindowProcedure(IntPtr, OpenTK.Platform.Windows.WindowMessage, IntPtr, IntPtr)
   at OpenTK.Platform.Windows.Functions.DispatchMessage(OpenTK.Platform.Windows.MSG ByRef)
   at OpenTK.Platform.Windows.Functions.DispatchMessage(OpenTK.Platform.Windows.MSG ByRef)
   at OpenTK.Platform.Windows.WinGLNative.ProcessEvents()
   at OpenTK.GameWindow.Run(Double, Double)
   at _lYLQLGyldvbDG9rPQyiRVeIqQVp._EEzpApWBQHtHR4iMJabXK2wDvlA(_ex0VSgRAdtsvhANmJHZHaf9ATWt, System.String[])
   at _IcGByoJhapvESnm6vaOawAHbkeU._EEzpApWBQHtHR4iMJabXK2wDvlA(System.Threading.ThreadStart)
   at _lYLQLGyldvbDG9rPQyiRVeIqQVp._k39DsboSFqAvcX2gaWs5Tk5Zl6Q(System.String[])
 }