Erro no TWebEngine na versão 12.1. 2410 usando webapp

[cicerocruz]

Olá, estou migrando um fonte da 2310 para 2410 que usa o TWebChannel ao executar o método bLoadFinished ocorre o seguinte erro:

Error: Failed to execute 'postMessage' on 'Window': Invalid target origin 'about:blank' in a call to 'postMessage'.

{"type":8664,"comp":4511,"cJavaScript":"document.querySelector('textarea').value = ``"}

SyntaxError: Failed to execute 'postMessage' on 'Window': Invalid target origin 'about:blank' in a call to 'postMessage'.
at WaWebView.postMessage (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:9646:48)
at TWebEngineHook.MS_WEBENGINERUNJAVASCRIPT (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:40839:13)
at TWebEngineHook.execMessage (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:40801:21)
at TTerminalMessageHook.execComponentMessage (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:47925:16)
at TTerminalMessageHook.execMessage (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:47220:19)
at TTerminalMessageHook.execute (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:47205:25)
at <>/webapp/resources/js/webapp-10.0.14-frontend.min.js:52406:30
at Array.every ()
at BinaryThreadConnection.exec (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:52403:14)
at BinaryThreadConnection.onDataReceived (<>/webapp/resources/js/webapp-10.0.14-frontend.min.js:52337:10)

Código Exemplo:
Static Function HTML()
Local aSize := MsAdvSize()
Local nPort := 0
Local cPasta := "_analyzer"
Local cHtml := cPasta + "CrzDev.html"
Local oModal
Local oWebEngine
Private oWebChannel := TWebChannel():New()

//Se a pasta não existir, cria a pasta
If ! ExistDir(cPasta)
    MakeDir(cPasta)
EndIf

//Se o arquivo não existir, cria um vazio
If ! File(cHtml)
    MemoWrite(cHtml, "<h1>Arquivo não encontrado!</h1>")
EndIf

//Cria a dialog
oModal := MSDialog():New(aSize[7],0,aSize[6],aSize[5], "Página Local",,,,,,,,,.T./*lPixel*/)

    //Prepara o conector
    nPort := oWebChannel::connect()
    cCache := ""

    //Cria o componente que irá carregar o arquivo local
    oWebEngine := TWebEngine():New(oModal, 0, 0, 100, 100,/*cUrl*/, nPort)
    oWebEngine:SetHtml( MemoRead(cHtml) )
    oWebEngine:bLoadFinished := { | webengine, cUrlExe |;
	                                WebEngine:runJavaScript( "document.querySelector('textarea').value = `" + cCache + "`" ) }
    oWebEngine:Align := CONTROL_ALIGN_ALLCLIENT

oModal:Activate()

Return

HTML CrzDev.html Exemplo:

<title>CrzSqlDev</title>

Aguarde conectando ...

<textarea id="editor"> </textarea>