Thanks for the quick replies.

The call trace didn't really lead anywhere so I just threw in a slew of print statements and found out it was the cv::imshow() call. It seems like when you build opencv with qt, the opencv imshow windows use qt code and so the other qt thread believes the imshow window is also making a widget? Have you heard of this before?

Anyways, I believe thats the issue so I'm trying some work-arounds. Also what do you mean those headers are not standard, I thought stdio and stdlib were?

And ChrisW67, no the console-move command is moving win32 application console.