QT C++ Empty Console when compiling in Debug mode

Hi I started programming with QT 5.6
Im working with the C++ section.

When i open a new project with this "Hello World" and try to compile in debug mode it opens the console but its completly empty, at this point there are 3 processes in my taskmanager with the same name as my projekt name.
when i shut down the console and compile again there is every time 1 process added.
I can close all processes exept 2. there is no way to close,end,kill the processes.

when i open a new project i can comiple in release mode and most of the times it works at the beginning, but when im starting to change something in the code and compile again i just get a the console open but i dont get any output in there.
often is also cant close the console.

im using windows.
using MinGW.
installed qt in every way that was possible for me and got everytime the same problems

i dont know what to do any more.