Crash - Shotcut can crash when quickly dragging a clip to the start of the Timeline

What is your operating system?
Windows 10 Enterprise 64-bit (10.0, Build 19045) (19041.vb_release.191206-1406)

What is your Shotcut version (see Help > About Shotcut)?

Can you repeat the problem? If so, what are the steps?
(Please be specific and use the names as seen in Shotcut, preferably English. Include a screenshot or screen recording if you can. Also, you can attach logs from either View > Application Log or right-click a job and choose View Log.)

REPRO RATE: 5/5 attempts, reproduced on various different machines.


  1. Launch Shotcut.
  2. Open a video file by dragging it over Shotcut (.mkv and .DVR files were used during testing).
  3. Drag the video to the Timeline.
  4. Zoom out or in to see the entire clip on the timeline.
  5. Quickly drag the clip to the start of the timeline, and let go.
  6. Quickly drag the clip away from the timeline start, and let go.
  7. Repeat steps 5 and 6 back to back as quickly as possible, trying to drag the timeline through any lags that may occur.
  8. Observe Shotcut will crash.

Shotcut is observed to occasionally crash when moving a clip along the Timeline. This occurs when Snapping and unsnapping the clip to the start of the Timeline in quick succession. This might have to be repeated several times before Shotcut crashes, although, on rare occasions, Shotcut will immediately crash when performing the above repro steps.

Video attached.

1 Like

Thanks for the excellent report. With the step-by-step instructions and the video, the steps to reproduce are very clear. This is exactly the kind of report we want to see.

I tested with some .mkv files that I have using your steps. Unfortunately, after more than 50 tries, I’m not able to reproduce a crash. Maybe there is some other factor about your computer or clip that is different than my test. I would be interested to know if anyone else can or can not reproduce it.

In addition to the listed machine, I was also able to reproduce the issue on the machine listed in this DxDiag. This issue happens often when I am moving very fast during my workflow.

Please let me know if there is a way to help diagnose the issue further, e.g. crash log generation, setting screenshots, etc. I can also attempt a repro with any given file and report back with a video.

Thank you for taking time to look at this issue.

DxDiag_kzz.txt (108.6 KB)

It relates to the same bug when piece of audio/video take wrong position after movement.

For example, when audio cut moved to another position but something goes wrong and it’s real position not changed but piece painted in new location. Audio plays as before from old position instead of new. Any other movements of this piece lead to crash.

I tried to reproduce this bug on my Linux laptop, but I couldn’t, because the first click on a clip doesn’t allow you to select it instantly; there’s a slight delay. But then I discovered a bug: if you click on a clip and then very quickly use a second click to drag the clip to the right, the rectangular frame will peel off from the clip and move two rads further.