R6025 Pure virtual function call error when exiting program

[Song_G_]

I am writing a face tracking program. It displays color image. Whenever the program closes, It shows the R6025 error, which says pure virtual function call.

It disappears when I comment out the code to convert PXCMImage to Writablebitmap. Can someone help to figure out what causes the error? Thanks!

public WriteableBitmap Convert2Image(PXCMCapture.Sample sample)
        {
            PXCMImage.ImageData data;
            sample.color.AcquireAccess(PXCMImage.Access.ACCESS_READ, PXCMImage.PixelFormat.PIXEL_FORMAT_RGB32, out data);
            WriteableBitmap wbmp = data.ToWritableBitmap(STREAM_WIDTH, STREAM_HEIGHT, 96.0, 96.0);
            sample.color.ReleaseAccess(data);
            return wbmp;
        }

[Song_G_]

Solved the issue after debugging line by line.

The error is caused by function call between threads (mine is wpf UI thread and realsense thread).

sensemanager.StreamFrames(false) will use a different thread.

Hope this can help someone.