What is your operating system?
Manjaro Linux 64 Bit, i5-9400 32 GB RAM, GTX 1660 Ti
What is your Shotcut version (see Help > About Shotcut)?
AppImage 23.05.14 worked better than AppImage 23.07.29
Can you repeat the problem? If so, what are the steps?
I did use 333 jpgs to generate a slideshow repeating the jpgs 5 times to get to a 12h video.
After adding the slideshow 4 times Shotcut did run out of memory without a crash.
Then I did restart Shotcut by force and it just needed around 15GBs.
I did add the next repeated slideshow, saved everything restarted Shotcut.
Than I did add only a few jpgs to meet my 12h goal, saved everything restarted Shotcut.
The currently newest version could not handle the big project on my pc so I did switch to AppImage 23.05.14.
Then I did try to export and my computer crashed because melt and Shotcut needed to much RAM (no Bug!). For running melt alone I did create another help topic.
What I also did notice was the adding of the slideshow to the video track got very slow after repeating the process a multiple times.