Hi, QPushButton::hitButton() is only present starting with Qt 5.15.0, in earlier releases (Qt 5.1 to Qt 5.14.2) Qt instead will use QAbstractButton::hitButton().
Maybe you've built part of your project with 5.15.0?
I didn't think so, but it appears that VS Tools for 2019 shares its settings with VS Tools 2017, so it appears it was building at least partially with 15.5.0.
