SUMMARY (I think the title is quite clear about the issue) STEPS TO REPRODUCE 1. Render a project with video and separate audio files 2. While some output files already have been completed, at least one is still in process, shut down or crash kdenlive (or PC) OBSERVED RESULT At restart, kdenlive, when asked to restart this process, kdenlive insists (correctly) on already existing files: "Output file already exists. Do you want to overwrite it?" This is correct, and wrong at the same time, because e.g. the video file has already been completed, only rendering an audio output file was interrupted. There is no way to resume (redo) the the rendering process of that second or further file, and skipping the overwrite of the already fully and correctly rendered file(s) of this project. EXPECTED RESULT It is expected, that a completed and correct file out of this project will not be overwritten. Instead, rendering ought to resume / restart with the first file out of this project that is yet incomplete.