I've just created a new Language Resource Template, but after restarting Trados Studio 2017 I can no longer edit it. If I try to open the file, I get an error: An item with the same key has already been added. The stack trace shows this:

<ErrorMessage>An item with the same key has already been added.</ErrorMessage>
<Exception>
<Type>System.ArgumentException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
<ParamName />
<HelpLink />
<Source>mscorlib</Source>
<HResult>-2147024809</HResult>
<StackTrace><![CDATA[ at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at Sdl.LanguagePlatform.Core.Wordlist.LoadInternal(TextReader reader, Boolean ignoreComments)
at Sdl.LanguagePlatform.Core.Wordlist.Load(Stream stream, Boolean ignoreComments)
at Sdl.LanguagePlatform.Core.Wordlist.Load(Byte[] data, Boolean ignoreComments)
at Sdl.LanguagePlatform.TranslationMemoryApi.LanguageResourceBundle.get_Variables()
at Sdl.TranslationStudio.Common.TranslationMemory.LanguagePlatformUtilities.CopyLanguageResources(LanguageResourceBundle source, LanguageResourceBundle target)
at Sdl.TranslationStudio.Common.TranslationMemory.LanguagePlatformUtilities.CopyResourceBundles(LanguageResourceBundleCollection languageResourceBundles, ILanguageResourcesTemplate template)
at Sdl.TranslationStudio.Common.TranslationMemory.LanguagePlatformUtilities.CreateLanguageResourceGroupTemplate(ILanguageResourcesTemplate template)
at Sdl.TranslationStudio.TranslationMemoryManager.FileBasedLanguageResourceGroupTemplateManagementObject.EditLanguageResourceGroup()
at Sdl.TranslationStudio.TranslationMemoryManager.FileBasedLanguageResourceGroupTemplateManagementObject.ShowPropertiesDialog()
at Sdl.TranslationStudio.TranslationMemoryManager.Actions.ShowManagementObjectPropertiesAction.Execute()
at Sdl.Desktop.Platform.Implementation.CommandBars.ActionService.<>c__DisplayClass3.<ExecuteAction>b__2()
at Sdl.Desktop.Platform.Implementation.Services.Log.Resources(Object message, Action action)
at Sdl.Desktop.Platform.Implementation.CommandBars.ActionService.ExecuteAction(IAction action, ActionOrigin origin, Boolean allowToggle)
at Sdl.Desktop.Platform.WinForms.IgCommandBarAction.Execute()
at Sdl.Desktop.Platform.WinForms.IgCommandBarAction._lazyButtonTool_ToolClick(Object sender, ToolClickEventArgs e)
at Infragistics.Win.UltraWinToolbars.ToolBase.OnToolClick(ToolClickEventArgs e)
at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.OnToolClick(ToolClickEventArgs e)
at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.FireEvent(ToolbarEventIds id, EventArgs e)
at Infragistics.Win.UltraWinToolbars.ToolBase.OnToolClick()
at Infragistics.Win.UltraWinToolbars.ToolMenuItem.OnClick()
at Infragistics.Win.UltraWinToolbars.PopupMenuItemUIElement.DoClickProcessing(MouseEventArgs e)
at Infragistics.Win.UltraWinToolbars.PopupMenuItemUIElement.OnMouseUp(MouseEventArgs e)
at Infragistics.Win.TextUIElementBase.OnMouseUp(MouseEventArgs e)
at Infragistics.Win.ControlUIElementBase.ProcessMouseUpHelper(Object sender, MouseEventArgs e)
at Infragistics.Win.ControlUIElementBase.ProcessMouseUp(Object sender, MouseEventArgs e)
at Infragistics.Win.Utilities.ProcessEvent(Control control, ProcessEvent eventToProcess, EventArgs e)
at Infragistics.Win.UltraWinToolbars.PopupControlBase.OnMouseUp(MouseEventArgs e)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)]]></StackTrace>

I've tried renaming the file, restarting Trados, etc. but nothing works. Any ideas? This is the 3rd time this has happened.