OpenCV2.4.2 unhandled exception on VideoCapture-Collection of common programming errors

I just installed OpenCV2.4.2 and created an OpenCV project using CMake. I don’t get any compilation errors. I have several functions for processing images and I have 2 applications:

1- Processes data from a video

2- Processes simulated data.

Both applications are identical except from the data extraction from the video.

PROBLEM: The application processing video crashes with

Unhandled exception at 0x75d8a048 in program.exe Access violation reading location 0x049f08c0.

It crashes in this part of the code, when reading frames:

cv::VideoCapture _video;
while(1) 
{       
        // grab the frame
        _video >> frame;  = 2) in unknown function, file ..\..\..\
src\opencv\modules\core\src\matrix.cpp, line 268
OpenCV Error: Assertion failed (0

Originally posted 2013-11-06 03:08:16.