<!-- 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. 

{
#ifdef Q_OS_MAC
    
    appMenuBar = new QMenuBar();
#else
    
    appMenuBar = menuBar();
#endif
    
    QMenu *file = appMenuBar->addMenu(tr("&File"));
    if(walletFrame)
    {
        file->addAction(m_open_wallet_action);
        file->addAction(m_close_wallet_action);
        file->addSeparator();
        file->addAction(openAction);
        file->addAction(backupWalletAction);
        file->addAction(signMessageAction);
        file->addAction(verifyMessageAction);
        file->addSeparator();
    }
    file->addAction(quitAction);
    QMenu *settings = appMenuBar->addMenu(tr("&Settings"));
    if(walletFrame)
    {
        settings->addAction(encryptWalletAction);