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Cannot fix "Failed to add window command bar extensions." with Studio 2021

The following error keeps occurring with Studio 2021:

<SDLErrorDetails time="2020/08/12 10:30:41">
  <ErrorMessage>Failed to add window command bar extensions.</ErrorMessage>
  <Exception>
    <Type>Sdl.Desktop.Platform.StudioException, Sdl.Desktop.Platform, Version=16.0.0.0, Culture=neutral, PublicKeyToken=c28cdb26c445c888</Type>
    <HelpLink />
    <Source>Sdl.Desktop.Platform</Source>
    <HResult>-2146233088</HResult>
    <StackTrace><![CDATA[   場所 Sdl.Desktop.Platform.Implementation.StudioWindow.Init(IEventAggregator eventAggregator)
   場所 Sdl.Desktop.Platform.Implementation.Studio.CreateWindowInternal(Boolean setActive, IEventAggregator eventAggregator)
   場所 Sdl.Desktop.Platform.Implementation.Studio.Run(ISplashScreen splashScreen, IEventAggregator eventAggregator)
   場所 Sdl.TranslationStudio.Application.Launcher.RunApplication()]]></StackTrace>
    <InnerException>
      <Type>System.ArgumentNullException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
      <ParamName>input</ParamName>
      <HelpLink />
      <Source>System</Source>
      <HResult>-2147467261</HResult>
      <StackTrace><![CDATA[   場所 System.Text.RegularExpressions.Regex.Replace(String input, String replacement)
   場所 System.Text.RegularExpressions.Regex.Replace(String input, String pattern, String replacement)
   場所 Sdl.Desktop.Common.AccountIcon.Initials.ExtractInitialsFromName(String name)
   場所 Sdl.Desktop.Common.AccountIcon.AccountIcon.GenerateBitmapAccount(String accountName, Icon icon, Int32 size)
   場所 Sdl.BestMatchService.Contracts.Identity.V2.BusinessAccountTO.GetImage(Int32 size)
   場所 Sdl.BestMatchService.Contracts.Identity.V2.BusinessAccountTO.get_SmallImage()
   場所 Sdl.TranslationStudio.Common.LanguageCloud.LanguageCloudLoginAction.RefreshLanguageCloudSubscriptionActionStatus(ConnectivityStatus connectivityStatus)
   場所 Sdl.TranslationStudio.Common.LanguageCloud.LanguageCloudLoginAction.RefreshLanguageCloudSubscriptionActionStatus()
   場所 Sdl.TranslationStudio.Common.LanguageCloud.LanguageCloudLoginAction.OnInit(IStudioWindow window)
   場所 Sdl.Desktop.Platform.CommandBars.AbstractAction.Init(IStudioWindow window)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.ActionInfo.get_Action()
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.ActionService.GetAction(String id)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.Extensions.CommandBarExtensionRegistry.GetCommandBarItemWrappersFromActionDescriptor(IStudioWindow window, PluginCommandBarItemTarget target, Boolean contextMenuLocations, List`1 menuItemWrappers, List`1 applicationMenuItemWrappers, List`1 quickAccessToolbarItemWrappers, List`1 rightSideTabItemsToolbarItemWrappers, List`1 ribbonTabItemWrappers, List`1 ribbonGroupItemWrappers, List`1 toolBarItemWrappers, ActionDescriptor pluginActionDescriptor)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.Extensions.CommandBarExtensionRegistry.GetCommandBarItemWrappers(IStudioWindow window, PluginCommandBarItemTarget target, IConditionInitializer conditionInitializer, Boolean contextMenuLocations, List`1& menuItemWrappers, List`1& applicationMenuItemWrappers, List`1& quickAccessToolbarItemWrappers, List`1& rightSideTabItemsToolbarWrappers, List`1& ribbonTabItemWrappers, List`1& ribbonGroupItemWrappers, List`1& toolBarItemWrappers, List`1& toolBarDescriptors)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.Extensions.CommandBarExtensionRegistry.GetCommandBarItemWrappers(IStudioWindow window, IEnumerable`1 targets, IConditionInitializer conditionInitializer, Boolean contextMenuLocations, List`1& menuItemWrappers, List`1& applicationMenuItemWrappers, List`1& quickAccessToolbarItemWrappers, List`1& rightSideTabItemsToolbarWrappers, List`1& ribbonTabItemWrappers, List`1& ribbonGroupItemWrappers, List`1& toolBarItemWrappers, List`1& toolBarDescriptors)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.Extensions.CommandBarExtensionRegistry.AddPluginCommandBarItems(IStudioWindow window, IEnumerable`1 targets, ICommandBar menu, IRibbonApplicationMenu applicationMenu, IRibbonQuickAccessToolbar quickAccessToolbar, ICommandBar rightSideTabItemsToolbar, IToolBarManager toolBarManager, IRibbon ribbon, IConditionInitializer conditionInitializer)
   場所 Sdl.Desktop.Platform.Implementation.CommandBars.Extensions.CommandBarExtensionRegistry.AddWindowCommandBarExtensions(StudioWindow window)
   場所 Sdl.Desktop.Platform.Implementation.StudioWindow.Init(IEventAggregator eventAggregator)]]></StackTrace>
    </InnerException>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>Studio16</ProductVersion>
    <EntryAssemblyFileVersion>16.0.0.2838</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Pro</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1041</OperatingSystemLanguage>
    <CodePage>932</CodePage>
    <LoggedOnUser>ITP\jesse_good</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>DESKTOP-UAO59IV</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>67022748 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>

The problem is *even* if I delete the following folder, the error comes back the second time I open Studio 2021:

C:\Users\[User Name]\appdata\Roaming\SDL\SDL Trados Studio\Studio16

Also, I checked my Windows Updates, and I have the latest version (there are no more new updates)

EDIT:

My guess is the issue is with my SDL account, as it is associated with multiple accounts. Speaking of which when I try to sign in to my SDL account with Trados Studio, it gives me the "Cannot find page" browser error.

EDIT2:

Okay, verified that the error occurs only when I sign into my SDL account inside of Studio.