Error starting Studio 2021 Service ‘Sdl.TranslatioStudio.AlignmentEditor.IAlignmentEditorService’ could not be started. I've tried repairing and reinstalling with no joy

Error starting Studio 2021 Service ‘Sdl.TranslatioStudio.AlignmentEditor.IAlignmentEditorService’ could not be started. I've tried repairing and reinstalling with no joy.

The error details window then says "An item with the same key has already been added"

Here is the xml error file if that can help: 

<SDLErrorDetails time="26-Feb-21 10:04:20 AM">
  <ErrorMessage>Service 'Sdl.TranslationStudio.AlignmentEditor.IAlignmentEditorService' could not be started.</ErrorMessage>
  <Exception>
    <Type>Sdl.Desktop.Platform.Services.ServiceStartException, Sdl.Desktop.Platform, Version=16.0.0.0, Culture=neutral, PublicKeyToken=c28cdb26c445c888</Type>
    <HelpLink />
    <Source>Sdl.Desktop.Platform</Source>
    <HResult>-2146233088</HResult>
    <StackTrace><![CDATA[   at Sdl.Desktop.Platform.Implementation.Services.ServiceContext.GetLocalService[T]()
   at Sdl.Desktop.Platform.Implementation.Services.ServiceContext.GetService[T]()
   at Sdl.TranslationStudio.AlignmentEditor.Conditions.CurrentAlignmentCondition.OnServiceContextChanged()
   at Sdl.Desktop.Platform.Extensions.AbstractServiceContextAwareCondition.set_ServiceContext(IServiceContext value)
   at Sdl.Desktop.Platform.Extensions.AbstractConditionInitializer.InitializeCondition(ICondition condition)
   at Sdl.Desktop.Platform.Extensions.ConditionHelper.GetCondition(IExtension extension, ConditionResult conditionResult, IConditionInitializer initializer)
   at Sdl.Desktop.Platform.Implementation.ViewReference..ctor(StudioWindow window, ViewDescriptor descriptor)
   at Sdl.Desktop.Platform.Implementation.StudioWindow.Init(IEventAggregator eventAggregator)
   at Sdl.Desktop.Platform.Implementation.Studio.CreateWindowInternal(Boolean setActive, IEventAggregator eventAggregator)
   at Sdl.Desktop.Platform.Implementation.Studio.Run(ISplashScreen splashScreen, IEventAggregator eventAggregator)
   at Sdl.TranslationStudio.Application.Launcher.RunApplication()]]></StackTrace>
    <InnerException>
      <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.FileTypeSupport.Framework.Integration.PocoFilterManager.LoadFileTypeCache()
   at Sdl.FileTypeSupport.Framework.Integration.PocoFilterManager.LoadAllDefaultFileTypeDefinitions()
   at Sdl.FileTypeSupport.Framework.Integration.PocoFilterManager..ctor(Boolean autoLoadFileTypes)
   at Sdl.ProjectApi.Implementation.FileTypeConfiguration.get_StandardFilterManager()
   at Sdl.ProjectApi.Implementation.FileTypeConfiguration.get_FilterManager()
   at Sdl.TranslationStudio.AlignmentEditor.AlignmentEditorService.OnStart()
   at Sdl.Desktop.Platform.Services.AbstractService.Start(IServiceContext context)
   at Sdl.Desktop.Platform.Implementation.Services.ServiceContext.GetLocalService[T]()]]></StackTrace>
    </InnerException>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>Studio16</ProductVersion>
    <EntryAssemblyFileVersion>16.1.3.4096</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Pro</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1033</OperatingSystemLanguage>
    <CodePage>1252</CodePage>
    <LoggedOnUser>DESKTOP-90MD0G2\gregl</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>DESKTOP-90MD0G2</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>8284192 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>