When debug a program using QTcreator, First enter debug mode, press F10 to enter the single-step debugging mode. After several lines of code are executed, the debugging arrow suddenly disappears at a line of code. The debugging arrow is stuck and disappears. Pressing F10 and F5 again does not work. The problem persists after re-commissioning. Restarting the project or rebuilding the project cannot solve the problem.But It is work as i do the same operator in vs2017.