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Qt/QML : 0xc0000005: read access violation, QOpenGLFunctions_3_2_Compatibility::glBeginTransformFeedBack

  • I have to debug a program I didn't write myself and have difficulties finding the source of the error. While I run the program I get an error, sometimes it takes 10 seconds, sometimes 5 minutes. Every functionalities of the program are working though.

    The error is : Exception at 0x553d90a5, code: 0xc0000005: read access violation at: 0x0, flags=0x0 (first chance).

    My debugger stops in the thread 0 on the function QOpenGLFunctions_3_2_Compatibility::glBeginTransformFeedBack that I'm not sure how it is called since the program is mainly QML, I guess it is related to the scene3D part.

    What is the QML functions which starts the BeginTransformFeedBack function ?

    Update : it acutally seems that it doesn't come from the 3D but from the video displayed. By commentating the part of the code related to the source of the image it doesn't crash anymore :

    Image {
    objectName: "videoStreamFrame"
    cache: false
    anchors.centerIn: parent
    //source: "image://videostream/yellow"
    function reload() {
        var oldSource = source;
        source = "";
        source = oldSource;

    But I still don't see how to fix the bug.