src/vs/workbench/api/browser/mainThreadWebviews.ts/MainThreadWebviews/getWebviewResolvedFailedContent
class MainThreadWebviews:	public getWebviewResolvedFailedContent(viewType: string) {
		return `<!DOCTYPE html>
		<html>
			<head>
				<meta http-equiv="Content-type" content="text/html;charset=UTF-8">
				<meta http-equiv="Content-Security-Policy" content="default-src 'none';">
			</head>
			<body>${localize('errorMessage', "An error occurred while loading view: {0}", escape(viewType))}</body>
		</html>`;
	}