"Item with the same key has already been added"

[LameAntics]

I was trying to combine two mods for Wind Waker HD. I imported the assets from the smaller mod (which replaces the Hero's Charm mask) into the bigger mod (Linkle character). After successfully combining the mods, I go in-game only to find out the mask clipped into the face. So I went into blender to fix the issue with the mask geometry and when trying to import the new mask dae file I get an error saying "Item with the same key has already been added" I can choose to continue but Toolbox stays on a "Importing DAE" bar that stays indefinitely at 0%

The full error it gives me is this:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.ArgumentException: An item with the same key has already been added.
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at Bfres.Structs.FMDL.AddOjects(String FileName, ResFile resFileNX, ResFile resFileU, Boolean Replace) in C:\projects\switch-toolbox\File_Format_Library\FileFormats\BFRES\Bfres Structs\SubFiles\FMDL.cs:line 889
at Bfres.Structs.FMDL.Replace(String FileName) in C:\projects\switch-toolbox\File_Format_Library\FileFormats\BFRES\Bfres Structs\SubFiles\FMDL.cs:line 607
at Toolbox.Library.NodeWrappers.STGenericWrapper.ReplaceAction(Object sender, EventArgs e)
at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ToolStrip.WndProc(Message& m)
at System.Windows.Forms.ToolStripDropDown.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Loaded Assemblies **************
mscorlib
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9310.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/mscorlib.dll

Toolbox
Assembly Version: 1.0.2736.0
Win32 Version: 1.0.2736
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Toolbox.exe

System.Windows.Forms
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9251.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll

System
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9310.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll

System.Drawing
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll

Toolbox.Library
Assembly Version: 1.0.2736.0
Win32 Version: 1.0.2736
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Toolbox.Library.DLL

Microsoft.VisualBasic
Assembly Version: 10.0.0.0
Win32 Version: 14.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.VisualBasic/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll

System.Core
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9297.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll

System.Xml
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll

DirectXTexNetImpl
Assembly Version: 1.0.0.3
Win32 Version:
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/x64/DirectXTexNetImpl.dll

System.Configuration
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll

OpenTK
Assembly Version: 3.0.1.0
Win32 Version: 3.0.1
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/OpenTK.dll

Octokit
Assembly Version: 0.31.0.0
Win32 Version: 0.31.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Octokit.DLL

SFGraphics
Assembly Version: 1.0.6956.42501
Win32 Version: 1.0.6956.42501
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/SFGraphics.dll

OpenTK.GLControl
Assembly Version: 3.0.1.0
Win32 Version: 3.0.1
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/OpenTK.GLControl.dll

System.Net.Http
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Net.Http/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Net.Http.dll

FirstPlugin.Plg
Assembly Version: 1.0.2736.0
Win32 Version: 1.0.2736
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Plugins/FirstPlugin.Plg.dll

GL_EditorFramework
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/GL_EditorFramework.DLL

FlatBuffers
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Plugins/FlatBuffers.DLL

Syroot.NintenTools.NSW.Bfres
Assembly Version: 1.2.3.0
Win32 Version: 1.2.3.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Syroot.NintenTools.NSW.Bfres.dll

Syroot.Maths
Assembly Version: 1.5.3.0
Win32 Version: 1.5.3.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Syroot.Maths.DLL

Syroot.NintenTools.Bfres
Assembly Version: 1.2.3.0
Win32 Version: 1.2.3.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Syroot.NintenTools.Bfres.dll

Syroot.BinaryData
Assembly Version: 2.0.1.0
Win32 Version: 2.0.1.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Syroot.BinaryData.dll

WeifenLuo.WinFormsUI.Docking
Assembly Version: 3.0.6.0
Win32 Version: 3.0.6.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Plugins/WeifenLuo.WinFormsUI.Docking.DLL

Newtonsoft.Json
Assembly Version: 12.0.0.0
Win32 Version: 12.0.1.22727
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Newtonsoft.Json.dll

Syroot.NintenTools.NSW.Bntx
Assembly Version: 1.2.3.0
Win32 Version: 1.2.3.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Syroot.NintenTools.NSW.Bntx.dll

SPICA
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Plugins/SPICA.DLL

ZeldaLib
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/Plugins/ZeldaLib.DLL

System.Numerics
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll

Accessibility
Assembly Version: 4.0.0.0
Win32 Version: 4.8.9037.0 built by: NET481REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll

Anonymously Hosted DynamicMethods Assembly
Assembly Version: 0.0.0.0
Win32 Version: 4.8.9310.0 built by: NET481REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_64/mscorlib/v4.0_4.0.0.0__b77a5c561934e089/mscorlib.dll

SARCExt
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/Lib/SARCExt.dll

DirectXTexNet
Assembly Version: 1.0.0.3
Win32 Version: 1.0.0.3
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/DirectXTexNet.DLL

AssimpNet
Assembly Version: 4.1.0.0
Win32 Version: 4.1.0
CodeBase: file:///B:/Users/lamea/Desktop/Toolbox-Latest/AssimpNet.DLL

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

[Dominouce]

You won't believe me, but for me the solution was simple. All you have to do is export your model as .fbx instead of .dae (while reducing the mesh size to 0.01 in the export window - Switch Toolbox takes care of enlarging your object by x100) and you're done. I hope this helps (even if it looks simple).