Program stops after receiving signal - rosterHandling example from qxmpp library

I try to compile project rosterHandling from qxmpp library (Qt creator, Qt 5, MinGW, Windows)
There is signal rosterReceived() that is connected to slot rosterReceived(). So when program gets that signal it should use method rosterRecived(), but insted of that it stops when it gets signal(it works as same as I would put in that place breakpoint – program wait until I click to continue).
Program works (no errors), but it stops in that place and wait for my reaction.
If anyone know where problem is?