I’ve had this problem for a while. When i drag a video file from Windows Explorer to the playlist, it cuts off the last few minutes of the video. I can play the video in the viewer thing and i can put it onto the timeline and play it, but it always abruptly stops at a random time. I’m sure my files aren’t the problem, i’ve checked them all and it happens consistently. If i copy and paste the video in windows media player then put the copy into shotcut, it loads the entire video and works fine. It is pretty inconvenient though. Windows 7, 12gb RAM, (i don’t know anything about my processor other than that it has 8 cores).
I have a similar problem, whenever there is a cut the video will freeze for a few seconds yet the play head keeps moving and the audio plays. And when the video is exported the freezes are still there where there was a cut made.
that’s not really similar 
Also, you necroed a post where the OP was still active, lucky!
I do not reproduce this. This will probably not be addressed unless the FFmpeg library does. We get the duration from FFmpeg, and you can override it in Properties.