If `addrProxy` or `addrSeparateProxyTor` do not have a colon in the string somewhere in the QSettings storage, then attempting to open the options dialog will cause the entire program to crash.

I'm not sure if this is really a problem since it is impossible to make those strings not have colons in them from normal operation. In order to replicate this, you must modify what QSettings stores (a conf file in Linux and Registry in Windows).
case ProxyPortTor: {
            
            QStringList strlIpPort = settings.value("addrSeparateProxyTor").toString().split(":", QString::SkipEmptyParts);
            return strlIpPort.at(1);
        }
#ifdef ENABLE_WALLET
        case SpendZeroConfChange:
            return settings.value("bSpendZeroConfChange");
#endif
        case DisplayUnit:
            return nDisplayUnit;
        case ThirdPartyTxUrls:
            return strThirdPartyTxUrls;
        case Language:
            return settings.value("language");
        case CoinControlFeatures:
            return fCoinControlFeatures;
        case DatabaseCache:
            return settings.value("nDatabaseCache");
        case ThreadsScriptVerif:
            return settings.value("nThreadsScriptVerif");
        case Listen:
            return settings.value("fListen");
        default:
            return QVariant();
        }
    }
    return QVariant();
}
bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, int role)