<!-- Describe the issue -->
Hello evryone, I get nothing when I click in open wallet, I am new to bitcoin and expect to show something.

![BitcoinIssue](https://user-images.githubusercontent.com/39341595/57179721-5024fc00-6e9e-11e9-80dd-af5e4345be48.png)

I'am using Bitcoin Core (both in testnet and mainnet, didn't work) 0.18 on window 10. 

{
    QMainWindow::changeEvent(e);
#ifndef Q_OS_MAC 
    if(e->type() == QEvent::WindowStateChange)
    {
        if(clientModel && clientModel->getOptionsModel() && clientModel->getOptionsModel()->getMinimizeToTray())
        {
            QWindowStateChangeEvent *wsevt = static_cast<QWindowStateChangeEvent*>(e);
            if(!(wsevt->oldState() & Qt::WindowMinimized) && isMinimized())
            {
                QTimer::singleShot(0, this, &BitcoinGUI::hide);
                e->ignore();
            }
            else if((wsevt->oldState() & Qt::WindowMinimized) && !isMinimized())
            {
                QTimer::singleShot(0, this, &BitcoinGUI::show);
                e->ignore();
            }
        }
    }
#endif
}
void BitcoinGUI::closeEvent(QCloseEvent *event)