Crashing when using mask and size filter together

I found that Shotcut may crash when I using Mask: From File and Size, position & rotate filters at the same time.

This happened when I use some picture as a mask, but not every png will cause it. And everything was fine when I use the mask filter alone. I made those picture by inkscape, and I don’t know what is the difference between them that cause this bug.
Attached files are some examples, the circle one would cause crash and the another doesn’t.

I’m using version 21.05.18 on windows10 (64bit)

Confirmed, using 3840x2160 images with a 1920x1080 Video Mode.
Shotcut crashes immediately when applying Size, Position & Rotate.
Crash Log mask and size3 shotcut-log.txt (33.7 KB)


  1. Color clip on V1
  2. Color clip on V2 (different color)
  3. Apply Mask: From File to the color clip on V2
    a. Select custom and apply PNG or JPG (3840x2160) image
  4. Apply Size, Position & Rotate.

Not confirmed with 1920x1080 images used with 1920x1080 Video Mode.

I was only able to reproduce this when the filters are added to a color clip. Is that @Ghonich case too?

Yes, I was using two color clips to make a transition, and I didn’t noticed the resolution difference before.
The problem was fixed after I made it a 1920x1080 image. Thank you.

This is fixed for the next version 21.06