I can reproduce an issue with master; v0.17.1rc1 works fine.

Steps to reproduce:
- `bitcoin-qt -regtest`
- open Console window
- repeat `generatetoaddress 1 AN_ADDRESS` some times until crash

Crash occurs both on wayland and x11.

[debug.log](https://github.com/bitcoin/bitcoin/files/2690776/debug.log)

[wallets.zip](https://github.com/bitcoin/bitcoin/files/2690781/wallets.zip)
{
    overviewAction->setEnabled(enabled);
    sendCoinsAction->setEnabled(enabled);
    sendCoinsMenuAction->setEnabled(enabled);
    receiveCoinsAction->setEnabled(enabled);
    receiveCoinsMenuAction->setEnabled(enabled);
    historyAction->setEnabled(enabled);
    encryptWalletAction->setEnabled(enabled);
    backupWalletAction->setEnabled(enabled);
    changePassphraseAction->setEnabled(enabled);
    signMessageAction->setEnabled(enabled);
    verifyMessageAction->setEnabled(enabled);
    usedSendingAddressesAction->setEnabled(enabled);
    usedReceivingAddressesAction->setEnabled(enabled);
    openAction->setEnabled(enabled);
}
void BitcoinGUI::createTrayIcon(const NetworkStyle *networkStyle)
{
    assert(QSystemTrayIcon::isSystemTrayAvailable());
#ifndef Q_OS_MAC
    trayIcon = new QSystemTrayIcon(this);
    QString toolTip = tr("%1 client").arg(tr(PACKAGE_NAME)) + " " + networkStyle->getTitleAddText();
    trayIcon->setToolTip(toolTip);
    trayIcon->setIcon(networkStyle->getTrayAndWindowIcon());
    trayIcon->hide();
#endif
    notificator = new Notificator(QApplication::applicationName(), trayIcon, this);
}
void BitcoinGUI::createTrayIconMenu()