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->setChecked(true);
    if (walletFrame) walletFrame->gotoOverviewPage();
}
void BitcoinGUI::gotoHistoryPage()
{
    historyAction->setChecked(true);
    if (walletFrame) walletFrame->gotoHistoryPage();
}
void BitcoinGUI::gotoReceiveCoinsPage()
{
    receiveCoinsAction->setChecked(true);
    if (walletFrame) walletFrame->gotoReceiveCoinsPage();
}
void BitcoinGUI::gotoSendCoinsPage(QString addr)
{
    sendCoinsAction->setChecked(true);
    if (walletFrame) walletFrame->gotoSendCoinsPage(addr);
}
void BitcoinGUI::gotoSignMessageTab(QString addr)
{
    if (walletFrame) walletFrame->gotoSignMessageTab(addr);
}
void BitcoinGUI::gotoVerifyMessageTab(QString addr)