Topic: Failure in Visual Studio 2019
This is occurring in 2019 Enterprise 16.7.2, but it's been happening for several versions at least.
ViEmu just stops working after certain basic operations (delete word, enter insert mode). An error bar appears on the top of the edit window at roughly the same time. Disabling and reenabling ViEmu fixes it until you do one of those operations again:
These are the errors that appear in the log:
<entry>
<time>2020/09/09 15:39:23.207</time>
<type>Information</type>
<source>Web Editor</source>
<description>System.ArgumentException: Specified OLE variant is invalid.

at System.Runtime.InteropServices.Marshal.GetObjectForNativeVariant(IntPtr pSrcNativeVariant)

at Microsoft.VisualStudio.Html.Interop.CommandTargetToOleShim.TranslateInputArg(Guid& guidCommandGroup, UInt32 commandID, IntPtr variantIn)

at Microsoft.VisualStudio.Html.Interop.CommandTargetToOleShim.Exec(Guid& guidCommandGroup, UInt32 commandID, UInt32 commandExecOpt, IntPtr variantIn, IntPtr variantOut)</description>
</entry>
<entry>
<time>2020/09/09 15:39:23.694</time>
<type>Error</type>
<source>Editor or Editor Extension</source>
<description>System.ArgumentException: Specified OLE variant is invalid.

at System.Runtime.InteropServices.Marshal.GetObjectForNativeVariant(IntPtr pSrcNativeVariant)

at Microsoft.VisualStudio.Html.Interop.CommandTargetToOleShim.TranslateInputArg(Guid& guidCommandGroup, UInt32 commandID, IntPtr variantIn)

at Microsoft.VisualStudio.Html.Interop.CommandTargetToOleShim.Exec(Guid& guidCommandGroup, UInt32 commandID, UInt32 commandExecOpt, IntPtr variantIn, IntPtr variantOut)

at Microsoft.VisualStudio.Editor.Implementation.CommandChainNode.InnerExec(Guid& pguidCmdGroup, UInt32 nCmdID, UInt32 nCmdexecopt, IntPtr pvaIn, IntPtr pvaOut)

at Microsoft.VisualStudio.Editor.Implementation.CommandChainNode.Exec(Guid& pguidCmdGroup, UInt32 nCmdID, UInt32 nCmdexecopt, IntPtr pvaIn, IntPtr pvaOut)

at Microsoft.VisualStudio.Editor.Implementation.CommandHandlerServiceAdapter.<>c__DisplayClass18_0.<Exec>g__executeNextCommandTarget|1()

at Microsoft.VisualStudio.UI.Text.Commanding.Implementation.EditorCommandHandlerService.ExecuteStartingAtIndex[T](Func`3 argsFactory, FrugalList`1 buffersAndHandlers, Int32 startIndex, EditorCommandHandlerServiceState state, Action nextCommandHandler)

at Microsoft.VisualStudio.UI.Text.Commanding.Implementation.EditorCommandHandlerService.<>c__DisplayClass14_0`1.<ExecuteStartingAtIndex>b__2()

at Microsoft.WebTools.Languages.Shared.Editor.Completion.TypingCommandHandler.ExecuteChainedCommand(EditorCommandArgs args, Action nextCommandHandler)

at Microsoft.WebTools.Languages.Shared.Editor.Completion.TypingCommandHandler.ExecuteCommand(EscapeKeyCommandArgs args, Action nextCommandHandler, CommandExecutionContext executionContext)

at Microsoft.VisualStudio.UI.Text.Commanding.Implementation.EditorCommandHandlerService.<>c__DisplayClass14_1`1.<ExecuteStartingAtIndex>b__0()

at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.CallExtensionPoint(Object errorSource, Action call, Predicate`1 exceptionFilter)
--- End of stack trace from previous location where exception was thrown ---

at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)</description>
</entry>