关于#qt#的问题：代码如下：void MainWindow::failure(){ Failure *fail = new Failure(this)

QBackingStore::flush() called for QWidgetWindow(0x202c46b0a90, name="MainWindowWindow") which does not have a handle.这个报错要如何解决

代码如下：
void MainWindow::failure(){
Failure *fail = new Failure(this);
if(startXlist[0]<40||startXlist[0]>420||startYlist[0]<70||startYlist[0]>330){
this->close();
fail->show();

}

}
进入if语句，this会关闭，但fail不会打开