cv::waitKey() throwing an exception all of a sudden but only in Debug mode

OpenCv 4.53, VS 2017, Win10, C++

All of a sudden in Debug mode I am getting this exception with cv:::waitkey

Exception thrown at 0x7904BC81 (opencv_highgui453d.dll) in MDI_VSDPV.exe: 0xC0000005: Access violation reading location 0x00000008. occurred

I have rebuilt the VS solution. Closed and Started VS, Rebooted the computer.

Has anyone ever run into this?

Ed