I tried to render a large video to the HuffYUV file format. When I looked at the monitor in the morning I saw a pop-up window that said some program (sorry I did not write down the name) had stopped unexpectedly. It also said that there was not enough free memory to analyze the problem. So, I clicked on "Ok" or something similar and the window went away and I closed Kdenlive. I may have forgotten some things that I did at that time. I suspect that I do not have enough RAM in my computer. I have ordered more. However, when I opened Kdenlive and tried to load the project, I got a pop-up window that said that Kdenlive could not find many files. I clicked on search recursively and set it to working. Nothing happened. So, I closed the program forceably and unplugged all of my external hard drives except the one on which the video program resided and tried again. This time the "Loading project" pop-up window came up, the program window got dark and nothing happened for maybe an hour until I again forceably closed the program. I started a new project and entered some videos, saved, closed Kdenlive and reopened it. The new project loads successfully. Then I uninstalled Kdenlive and reinstalled it. No change. I also tried to open an older saved version of the big project but that did not work either. So, I don't know what to do about this. I do not want to loose all of the hard work I put into the long video. The new, larger, RAM has not arrived yet but when it does, I will install it and try again but I am not too hopeful that that will help since I was able to load the project before this "Rendering" incident happened. Any ideas about what to do? I am using Ubuntu 16.04 and Kdenlive is 16.12.3.

I just installed additional RAM but this did not solve the problem. I went from 8 GB to 16 GB.