QObject::killTimers: timers cannot be stopped from another thread

[CarlBonzi]

It cause a problem look like "QObject::killTimers: timers cannot be stopped from another thread", here is my code

HtmlToPdf htmlToPdf = HtmlToPdf.create().object(HtmlToPdfObject.forHtml(html).defaultEncoding("utf8"));

try(InputStream in = htmlToPdf.convert()) {
    String base64 = Base64.getEncoder().encodeToString(IOUtils.toByteArray(in));
    htmlToPdf.finished(null);
    System.out.println(LocalDateTime.now());
    System.out.println(base64);
}