How to use Qt5's new signal-slot connect function in CLion?

I'm developing application with Qt5. When I use the new signal-slot connect function, CLion show me an error, saying "Incompatible pointer types 'const char * ' and ''void (*)(bool)' ". How should I do, thanks!

This is my code.

connect(openAction, &QAction::triggered, this, &MainWindow::openFile); // openFile is an member function in MainWindow