Unsolved Why in WebEngineEngineView Play flash prompt "Couldn’t load Plugin"??

[jenk]

QWebEngineSettings::globalSettings()->setAttribute(QWebEngineSettings::PluginsEnabled, true);
QWebEngineView * webengineview=new QWebEngineView();
webengineview->load(QUrl("http://127.0.0.1/test.html"));
webengineview->show();

Use safari play is ok。

[jenk]

OS X install the latest flash palyer.