I've got a Kdenlive project where I imported several large (>1GiB, several minutes in length) video files. This project usually crashes Kdenlive, about half a minute after opening it. Since the size of the video files is the only thing that's different to my usual projects (up to half an hour long, not crashing ever), I thought that maybe Kdenlive can't handle any files this big?

If anyone has any solutions for this problem, please reply below.

Important is, that the project settings matches the clip size and fps (I.e 1080p 50fps). Make sure all clips which you import match the project settings otherwise some effect doesn’t work. It will take some time to analyze the clip (I assume by FFMPEG) but Kdenlive should not crash. If Kdenlive still crash try to cut the long clip into smaller pieces in another program like VirtualDub.