After this question I found that OpenCV gives me this error:
Starting C:\\Users\\nikola\\Documents\\build-ConsoleTry-Desktop_Qt_5_5_0_MSVC2013_64bit-Deb
Micka is right - it do need highgui, so I have copied all .dll files from D:\opencv_2411\opencv\build\x64\vc12\bin to debug directory. I was having hadeaches because before this I have copied all .dll files from my Visual Studio 2013 project directory, but they were x86, and the QT project is x64. Thank you all!!! And if someone still have problem see this topic too.